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Background:
Study Protocol

Investigating the Impact of Pressure Relief Performance on the Occurrence of Pressure Injuries and Shoulder Pain in Wheelchair Users with Spinal Cord Injury (PRperf Study): Study Protocol for a Prospective Observational Study

by
Yannik Schürch
1,2,
Anneke Hertig-Godeschalk
1,
Inge Eriks-Hoogland
1,2,3,
Anke Scheel-Sailer
1,2,4,
Martin W. G. Brinkhof
1,2 and
Ursina Arnet
1,*
1
Swiss Paraplegic Research, 6207 Nottwil, Switzerland
2
Faculty of Health Sciences and Medicine, University of Lucerne, 6005 Lucerne, Switzerland
3
Swiss Paraplegic Centre, 6207 Nottwil, Switzerland
4
Centre for Rehabilitation and Sports Medicine, Insel Group, University Hospital, University of Bern, 3010 Bern, Switzerland
*
Author to whom correspondence should be addressed.
Methods Protoc. 2025, 8(3), 62; https://doi.org/10.3390/mps8030062
Submission received: 11 April 2025 / Revised: 30 May 2025 / Accepted: 4 June 2025 / Published: 6 June 2025
(This article belongs to the Section Public Health Research)

Abstract

Background: Pressure injuries (PIs) and shoulder pain (SP) are frequent problems in individuals with spinal cord injury (SCI), affecting both quality of life and healthcare use. Although pressure relief (PR) is recommended to prevent PIs, it is often not performed regularly, and its long-term benefits remain unclear. Furthermore, some PR methods may contribute to SP, resulting in conflicting clinical guidelines. This study aims to objectively measure PR performance and investigate its long-term relationship with PI and SP. Methods: This study is a longitudinal observational study involving 70 manual wheelchair users with complete SCI. Over one year, participants attend five study visits to assess confounding factors such as comorbidities and shoulder range of motion. PR performance (technique, frequency, duration) is continuously monitored for three weeks after each of the first four visits using textile measurement mats, while SP is assessed weekly with a questionnaire. Causal associations with PI and SP will be examined using directed acyclic graphs and multivariable regression modelling. Results: The study is ongoing. Long-term objective data on PR performance will provide insights into its relationship with PI and SP. Conclusions: Findings will inform clinical practice and contribute to improved evidence-based PR guidelines for individuals with SCI.

1. Introduction

Pressure injuries (PIs) and shoulder pain (SP) are two highly prevalent and consequential secondary health conditions among individuals with spinal cord injury (SCI) who rely on a wheelchair for mobility and activities of daily living [1,2,3,4,5,6]. A PI is a localised damage to the skin and underlying soft tissue caused by intense and/or prolonged pressure or pressure in combination with shear [7,8]. Prolonged immobility, such as sitting in one position, is a risk factor for PIs, placing individuals with reduced mobility—such as wheelchair users with SCI—at a high risk of developing PIs [8]. In persons with SCI, prolonged pressure (e.g., on the buttocks) does not trigger feedback to elicit movement, unlike in persons without sensory or motor deficits. This lack of feedback can potentially lead to skin breakdown [8,9]. Other factors, such as completeness of lesion, independence in activities of daily living, or weight, can further influence the risk of developing PIs [10,11]. SP is likely the result of a disbalance between shoulder capacity and load caused by repetitive or strenuous tasks such as wheelchair propulsion, transfers, or reaching from a seated position [12]. Although the episodic onset of PIs is distinct from the chronic nature of SP, both health problems have a substantial impact on the individual and result in notable direct and indirect healthcare and societal costs [13,14,15,16,17].
Performing intermittent pressure relief (PR) is considered as one of the most effective strategies for preventing PI acquired from sitting [9,18]. PR is a movement that shifts the body weight off the buttocks, most commonly achieved by leaning forward or sidewards or pushing off the buttocks from the wheelchair cushion using both arms (i.e., PR lift) [19,20]. All three PR techniques have been shown to be effective and cost efficient for increasing oxygenation and blood flow in the buttocks [18,21]. However, the PR lift is also considered a risk factor for SP, as it places an additional load on the shoulders, which are already heavily loaded from activities of daily living [22,23,24]. Despite a shift in clinical recommendations towards adopting the PR techniques forward and side lean [25,26,27], the majority of wheelchair users still use the PR lift [19]. It also remains to be shown whether the forward and side lean are less likely to cause SP and whether they are as effective in preventing PIs as a PR lift. Clinical guidelines for PR recommend implementing pressure-relieving manoeuvres ranging from 15 s every 15 min to 60 s every hour. Based on self-report assessments and short-term measurements of approximately one week, the performance of PR (“PR performance”) in wheelchair users typically does not meet these guidelines [19,28]. Since self-reported assessments of PR performance may not be reliable [29], studies using objective measures to assess PR performance are needed. Furthermore, the long-term effectiveness of PR in preventing PI remains unclear, which highlights the need for long-term measurements.
To align and improve the current recommendations regarding PI and SP prevention, we present the protocol for our study to investigate the impact of PR performance on the occurrence of PI and SP in manual wheelchair users with SCI. The aim of this study is to contribute to an in-depth understanding of PR performance in the daily lives of wheelchair users with SCI and its complex association with the occurrence of PI and SP. The use of novel textile measurement mats [30] will facilitate the objective, individual quantification of PR performance in daily life several times over the course of one year. To account for the multifactorial nature of PI development, we will comprehensively assess a broad range of potential confounders, including physiological, psychological, and lifestyle factors (Appendix A, Table A1). We hypothesise that a higher relative PR time is related to a lower incidence of PI independent of the PR technique. Furthermore, we hypothesise that between-person differences in PR technique, but not in relative PR time, are related to the prevalence of SP.

2. Materials and Methods

2.1. Study Design and Participants

This longitudinal observational study investigates the impact of PR performance on the occurrence of PI and SP in manual wheelchair users with SCI (Figure 1). The study protocol was designed according to the Standard Protocol Items: Recommendations for Interventional Trials 2013 Statement [31] (Supplement S1). The study is planned to run from March 2024 (first study visit) to March 2026 (last study visit). Study visits will take place either at the study centre (Swiss Paraplegic Research, Nottwil, Switzerland) or at the participant’s place of residence. Participants will receive compensation for travel and time expenses. This project is a nested project of the population-based Swiss Spinal Cord Injury cohort study (SwiSCI) [32].
Recruitment for this study is primarily carried out by screening the SwiSCI database for eligible participants. Individuals fulfilling the inclusion criteria according to the database are informed by the SwiSCI study centre about this study and invited to participate. Additional participants will be recruited through healthcare professionals and outpatient clinics at the four specialised SCI centres in Switzerland. Finally, information and calls for participation will be disseminated through magazines and social media channels of the SCI community. Individuals who express interest in participating in the study will be scheduled for a screening visit, which will be conducted either via phone or in person. During this visit, the inclusion and exclusion criteria (Table 1) will be reviewed to assess eligibility. Written informed consent (Supplement S2) is obtained from all participants prior to study initiation by qualified study employees.
We estimated the minimal sample size needed to detect the effect of PR performance (exposure of interest) on PI occurrence over time (outcome of interest). The hazard ratio was defined as the measure of effect [33]. Using the power calculation platform for proportional hazards regression (here, a Cox model) in Stata Version 18.0, the minimal sample size was calculated across a range of plausible hazard ratios for the event of a PI related to differences in PR performance (delta), while employing a plausible range of population-average probabilities for the event of a PI over the one-year study period.
Combining data on PI incidence from the SwiSCI community survey conducted in 2017 [34] with evidence from previous studies [35,36,37,38] on the comparative incidence of sitting-related PI’s, we obtained a minimal one-year event probability of a newly acquired sitting-related PI of approximately 0.3 to 0.4 for the study population. Using a conservative event probability of 0.3 and presuming a power (1 − β) of 0.8 as well as a significance level α of 0.05, the power calculation indicated that an achievable sample size of 60 participants supports the detection of hazard ratios of approximately 3.1 or higher (Figure 2).
Hazard ratios of such magnitude are plausible in SCI, as shown by Verschueren et al. [38], who analysed predictors of PI and reported adjusted odds ratios of 5.0 for the lesion level (tetraplegia vs. paraplegia). PR performance is seen as an important mediator from lesion level to PI development, since the ability to perform PR regularly decreases with higher lesion level.
A preliminary screening of the SwiSCI database in February 2024 identified 373 eligible individuals. We expected that approximately 75% would be eligible for participation. If 20% were willing to participate, we would have approximately 60 participants. With the additional recruitment within specialised SCI clinics, the recruitment of 70 participants is feasible.

2.2. Study Procedures and Outcomes

Study participation includes five visits over the course of one year (Figure 1). Trained study employees perform all assessments according to a standardised protocol. An overview of the study procedures, including the time points at which each outcome and confounder will be assessed, is provided in the Appendix A (Table A1). The initial visit (T1) takes place at the study centre. Individual characteristics and potential confounding factors for PI and SP are collected using interviews, questionnaires, and non-invasive assessments. Potential confounders were identified based on the literature or expert opinion. Considering the multifactorial nature of PI and SP, including a wide range of confounding variables allows the estimation of each participant’s individual risk for PI and SP beyond their PR behaviour. PI occurrence will be self-reported and classified according to the National Pressure Injury Advisory Panel (NPIAP) staging system [7]. After T1, participants are assessed every three months (T2 to T5) either at the study centre or at their homes, depending on their personal preference. At each visit, the confounders for PI and SP are reassessed. At the end of each of the first four visits (T1 to T4), a textile measurement mat (Sensomative wheelchair, Sensomative GmbH, Rothenburg, Switzerland; Figure 3) is placed underneath the wheelchair cushions to quantify PR performance during the following three weeks (T1+ to T4+). The measurement mat includes 12 piezo-resistive textile sensors, each with a size of 4 cm × 4 cm which are distributed over the area of the mat (31 cm × 31 cm). Each sensor is continuously measuring pressure with a frequency of 5 Hz (pressure range: 0–60 kPa, resolution: 8 bits). The data of all sensors are transmitted to a connected data storage device using Bluetooth Low Energy. Following the method previously described by Hubli et al. [30], a calibration of the different PR techniques (PR lift, side lean, forward lean, and individual technique) is performed before and after each measurement, which allows for the classification of individual data. To ensure its position during the entire measurement period, the mat is fixed to the wheelchair cushion using tape or Velcro, depending on the type of the cushion.
Furthermore, an inertial measurement unit (IMU; Axivity AX6, Axivity Ltd., Newcastle upon Tyne, UK) sensor is attached to the wheel (Figure 4) to measure wheelchair mobility metrics as described by De Vries et al. [39] (i.e., distance covered, linear velocity of the wheelchair, number and duration of pushes, and number and magnitude of turns; measurement frequency: 100 Hz). Shoulder pain is assessed weekly at the end of each measurement week using the Wheelchair User’s Shoulder Pain Index (WUSPI) [40]. The WUSPI provides a validated tool for measuring shoulder pain intensity during functional activities of daily living in wheelchair users. This measure was selected to capture general activity-related shoulder pain that reflects the cumulative impact of daily shoulder loading, of which PR lifts are a significant contributor [22]. Furthermore, specific WUSPI items, such as transfers, may help relate shoulder load during PR lifts to SP. To ensure compliance with completing the WUSPI, participants will receive weekly reminders through their preferred communication channel (e.g., email or phone). If a PI occurs during the study, a final visit (Tocc) takes place according to the regular schedule and no further measurements or visits are conducted afterwards.
In the event of a sensor malfunction, data loss, or insufficient data quality, the respective measurement period will be repeated whenever feasible within the study timeline. If repeating a measurement is not possible, incomplete data from the affected measurement period will be excluded from analysis. Sensitivity analyses will be performed to assess potential bias resulting from missing data.
A comprehensive list of all study parameters and their corresponding assessments is provided in Appendix A (Table A1). At T1, individual characteristics and all confounders are assessed using interviews, questionnaires, or non-invasive assessments. PI occurrence, severity, and location are assessed at each visit. Parameters with high variability over time are also assessed from T2 to T5/Tocc. Other confounders are only assessed if the participants report changes since the previous visit. During the three-week measurement periods (T1+ to T4+), PR performance (including PR technique, PR frequency [times per seated hour], and PR duration [s]) is assessed continuously using the Sensomative measurement mat, and wheelchair mobility is measured with an IMU sensor. During the measurement periods, SP is assessed weekly using the WUSPI, a reliable and validated tool measuring shoulder pain intensity during functional activities of daily living in wheelchair users [40].
Researchers as well as clinicians with experience in the field of SCI were involved in the design of the study protocol. The study procedures were discussed and extensively tested with individuals with SCI. During these pilot tests, feedback was provided on the procedures, wearability, and the potential burden of study participation. It was reported that the sensors were not noticed during daily activities, nor did they lead to behavioural changes. Compliance with sensor use was high. To further reduce participant burden and increase adherence, study visits can also take place at the participant’s home.
This publication is based on version 2.0 of the study protocol, dated 19 February 2024. Recruitment began on 13 March 2024, and data collection is estimated to end in July 2026.

2.3. Quality Assurance and Safety Provisions

Data capture and management are performed using the web-based system SecuTrial (Interactive Systems, Berlin, Germany), which fulfils Good Clinical Practice requirements. Within the database, which is managed by a study-independent data manager, each study employee has predefined rights according to their role in the study. Errors during data entry are minimised by built-in control mechanisms and plausibility rules. The sensor data are stored on a secure server that only authorised study personnel have access to. Each participant is assigned a unique identification code. Documents allowing the identification of participants are stored separately on a secure server.
In addition to the safety measures concerning data management, the Swiss Paraplegic Research Clinical Trial Unit is assigned to perform study monitoring according to the study-specific monitoring plan. The monitoring plan is based on the risk-adapted monitoring approach described in the ADAMON study [41]. All source data and documents are accessible to the monitors. A monitoring report is made after every monitoring visit.
All assessments and study procedures are non-invasive and are expected to pose no excessive risks or burden to the participants. Quality measures are in place to minimise the risk of unauthorised data access or the unintentional identification of participants. Serious events are documented and reported to the Sponsor-Investigator and the responsible Ethics Committee during the entire study period.
Participants are allowed to withdraw from the study at any time without providing a reason. Participants are excluded from the study if the eligibility criteria are no longer fulfilled. In the event of exclusion or withdrawal of consent, all data collected up to this point are used in coded form for the analysis.

2.4. Data Analysis Plan

Processing of the data from the pressure measurement mat will be carried out as described by Hubli et al. [30]. During the individual calibration before and after the measurement period, the system is customised to account for individual characteristics by assessing the user’s different PR techniques and an upright reference sitting position. After the measurement period, the collected data—comprising twelve pressure values per measurement frame—are classified using a random forest supervised learning algorithm using the calibration data. The algorithm distinguishes between the regular sitting position and various PR positions. This classification approach was previously developed by Zemp et al. and has been validated and applied in several previous studies [30,42,43]. Furthermore, the pilot testing we conducted prior to the start of our study yielded good results in terms of accuracy, precision, and sensitivity. The daily duration of sitting time and the used PR techniques as well as the according duration and frequency will be analysed and described descriptively.
Statistical data analysis will be performed using the contemporary versions of the statistical software packages STATA (Version 18.0, StataCorp LLC, College Station, TX, USA), R (Version 4.5.0, GNU General Public License, Free Software Foundation, Boston, MA, USA), RStudio (Version 2025.05, Posit PBC, Boston, MA, USA), Matlab (Version R2025a, MathWorks, Natick, MA, USA), and Python (Version 3.13.4, Python Software Foundation, Wilmington, DE, USA). The data analysis plan includes the use of basic descriptive statistics, as well as univariable and multivariable regression models that are appropriate for the error distribution of the outcome at stake. Descriptive and univariable statistics will be used to describe the study population and the outcomes at the different measurement points. Univariable analyses of between-group differences will make use of basic statistics, including chi-squared or Fisher’s exact tests for categorical variables and t-tests or non-parametric Kruskal–Wallis tests for continuous variables. Descriptive analysis of time-to-event outcomes (PI occurrence) will include Kaplan–Meier and Nelson–Aalen cumulative hazard function plots. The assessment and updating of a wide range of potentially confounding parameters (Appendix A, Table A1) allows for statistical control of within-person and between-person variation in the primary outcomes and helps to understand the complex association of PR performance with PI and SP. Furthermore, support for a causal association of PR performance with PI and SP will be inferred using directed acyclic graphs and multivariable regression modelling. To account for missing data in multivariate analysis, we will use the method of multiple imputation using chained equations and assuming missing data at random [44]. To assess the robustness of the findings, pattern mixture sensitivity analysis will be considered for scenarios indicating substantial missingness (>10%) of a non-random pattern nature [45].
No interim analyses are planned for this study. In case of a serious event, the study will be stopped until a safety review is completed. In such cases, interim analyses will be performed.

2.5. Dissemination Policy

The results of this study will be published in peer-reviewed journals and presented at scientific conferences. Results will also be disseminated through newsletters and the online media of the Swiss Paraplegic Association. Individual results will be shared with the participants at the end of the study. Anonymised data and statistical codes will be made available upon request.

3. Strengths and Limitations

One of the key strengths of this study is that it is the first to objectively assess pressure relief performance in the daily lives of participants with SCI over an extended period of time. The longitudinal design with multiple measurement time points offers valuable insight into PR performance in daily life. Compared to previous studies, which measured PR performance over shorter periods or relied on self-reports, our study design enables us to provide more reliable information on PR performance in daily life. Furthermore, it allows us to infer causality in the complex relationship between PR performance, PI, and SP. The evaluation of a wide range of relevant confounders, which were selected based on the literature and expert opinion, allows us to investigate the relationship even more comprehensively. We acknowledge that achieving the target sample size of 70 participants may be challenging, given the limited size of the target population of individuals with complete SCI living in Switzerland per se as well as the relatively long duration of participation for the participants. Nevertheless, we are confident that we will be able to achieve this sample size using the different recruitment strategies presented.

4. Outlook

The results of this study provide valuable insight into the complex relationship between PR performance, PI, and SP. This can support clinical decision making and improve clinical guidelines for PR. Furthermore, this study will establish a foundation for future interventional research on PR performance. Such studies may involve the comparison of different PR strategies with respect to their effectiveness in preventing PI and/or SP. The ultimate objective is to reduce the incidence of both PI and SP in community-dwelling individuals with SCI.

Supplementary Materials

The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/mps8030062/s1, Supplement S1: SPIRIT Checklist for the study protocol of the PRperf study; Supplement S2: Participant information and informed consent form.

Author Contributions

Conceptualisation, U.A., I.E.-H. and A.S.-S.; methodology, M.W.G.B.; investigation, U.A., A.H.-G. and Y.S.; writing—original draft preparation, Y.S.; writing—review and editing, U.A. and A.H.-G.; supervision, U.A. and A.H.-G.; project administration, Y.S.; funding acquisition, U.A., I.E.-H. and A.S.-S. All authors have read and agreed to the published version of the manuscript.

Funding

This research was funded by the Research Committee of the Swiss Paraplegic Foundation, grant number 2021-04. The funding body did not and will not have any role in the conception of the study design, data collection, management, analyses, interpretation of results, or writing of the publications.

Institutional Review Board Statement

This study will be conducted in accordance with the declaration of Helsinki as well as the good clinical practice guidelines and Swiss national regulations. The study was approved by the Swiss Ethics Committee for Northwest/Central Switzerland (EKNZ, 2024-00087, date of approval 27 February 2024). In the case of protocol modifications, the ethics committee will be notified, and participants will be updated. Regulatory authorities will be informed of the study’s end.

Informed Consent Statement

Informed consent will be obtained from all participants involved in the study.

Data Availability Statement

No new data were created or analysed in this study. Data sharing is not applicable to this article.

Acknowledgments

The authors wish to thank Mike Bucher and Tobias Höller for their willingness to test the study procedures and for sharing their experiences and valuable suggestions for improvement. Furthermore, the authors wish to thank Roland Zemp for providing the hardware for the PR measurements (Sensomative wheelchair, Sensomative GmbH, Rothenburg, Switzerland) and adapting it to our wishes.

Conflicts of Interest

The authors declare no conflicts of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results.

Abbreviations

The following abbreviations are used in this manuscript:
AISAmerican Spinal Injury Association Impairment Scale
EKNZSwiss Ethics Committee for Northwest/Central Switzerland
IMUInertial measurement unit
PIPressure injury
PRPressure relief
PRperfPressure relief performance
SCISpinal cord injury
SCIM-SRSpinal Cord Independence Measure Self-Report
SPShoulder pain
SwiSCISwiss Spinal Cord Injury cohort study
WUSPIWheelchair User’s Shoulder Pain Index

Appendix A

Table A1. Detailed assessments table of primary outcomes and confounders.
Table A1. Detailed assessments table of primary outcomes and confounders.
Exposure and Main OutcomesAssessment MethodParameter/UnitAssessment TimepointsLiterature
PR performanceMeasured using a textile sensor mat (Sensomative wheelchair, Sensomative GmbH, Rothenburg, Switzerland)PR technique (weight relief lift, forward lean, side lean, or other)
PR frequency (times/h)
PR duration (s)
T1+, T2+, T3+, T4+[30]
PI occurrenceQuestioningLocation and grade (following National Pressure Injury Advisory Panel (NPIAP) pressure injury stages 1 to 4, including unstageable pressure injuries)Screening, T1, T2, T3, T4, T5/Tocc[7,46]
SPWheelchair User’s Shoulder Pain Index (WUSPI)Score of 0 to 150 pointsT1+, T2+, T3+, T4+[40]
ConfounderAssessment MethodParameter/UnitAssessment TimepointsConfounder forLiterature
AgeQuestioningYearsScreeningPI, SP[11,12,36,47,48,49,50]
Alcohol consumptionQuestioningDays/week and units/dayT1, T2, T3, T4, T5/ToccPI[51]
Anxiety and depressionHospital Anxiety and Depression Scale (HADS)Score of 0 to 21 points for anxiety and depression, respectivelyT1, T2, T3, T4, T5/ToccPI, SP[48,52]
Autonomic dysreflexiaISAFSCI questionnaireBinary (yes/no)T1, T2, T3, T4, T5/ToccPI[10,53]
Bed rest during daytime/dayQuestioningHoursT1+, T2+, T3+, T4+PI
Diabetes mellitusQuestioningBinary (yes/no)T1, (T2), (T3), (T4), (T5/Tocc)PI[50,54,55]
Feverish infectionQuestioningBinary (yes/no)T1, T2, T3, T4, T5/ToccPI[10,54]
HeightQuestioningcmT1PI, SP
IncontinenceISAFSCI questionnaireScore of 0 to 2 pointsT1, T2, T3, T4, T5/ToccPI[11,48,53,54]
Independence in activities of daily lifeSCIM-SR questionnaireScore of 0 to 100 points; divisible into three subscalesT1, (T2), (T3), (T4), (T5/Tocc)PI, SP[10,54,55,56]
Lesion AISQuestioning, Medical recordScore of A to ET1, (T2), (T3), (T4), (T5/Tocc)PI, SP[2,10,12,36,49,55]
Lesion durationQuestioning, Medical recordYears since injuryScreeningPI, SP[12,22,36,47,49,57]
Lesion levelQuestioning, Medical recordC1 to S5T1, (T2), (T3), (T4), (T5/Tocc)PI, SP[2,12,22,49,57]
Medication intakeQuestioningType of medicationT1, T2, T3, T4, T5/ToccPI, SP[47,57]
Menopausal statusQuestioningBinary (menopause yes/no)T1, T2, T3, T4, T5/ToccPI
Mobility independenceSCIM-SR questionnaire—Mobility during short distances (10–100 m)Score of 0 to 8Screening, T1, T2, T3, T4, T5/ToccPI, SP[11,56]
MVPA duration/weekQuestioningHours/weekT1, T2, T3, T4, T5/ToccPI, SP
PI locationQuestioningLocationT1, T2, T3, T4, T5/ToccPI[11,48,55]
PI stageQuestioningStage 1 to 4T1, T2, T3, T4, T5/ToccPI[7,11,46,48,54]
PI treatmentQuestioningConservative/surgicalT1, T2, T3, T4, T5/ToccPI
Pressure relief qualityPressure mat (ForeSite SS, Xsensor, Calgary, Canada)% of pressure compared to upright sittingT1, (T2), (T3), (T4), (T5/Tocc)PI
RoM upper extremityGoniometerDegreesT1, (T2), (T3), (T4), (T5/Tocc)SP[22]
Rotator cuff functionBelly-Press Test (also Napoleon-Test)Binary (positive/negative)T1, (T2), (T3), (T4), (T5/Tocc)SP[58,59]
Self-efficacyGeneral self-efficacy scaleScore from 0 to 40T1, T2, T3, T4, T5/ToccPI, SP[60,61,62]
SexQuestioningBinary (male/female)ScreeningPI, SP[2,37,49]
Shoulder injuriesQuestioningType of injuryT1, (T2), (T3), (T4), (T5/Tocc)SP[12]
Shoulder interventionQuestioningType of interventionT1, (T2), (T3), (T4), (T5/Tocc)SP
Shoulder joint disease/pathologyQuestioningType of disease/pathologyT1, (T2), (T3), (T4), (T5/Tocc)SP[12,22,58]
Sitting time/dayQuestioning during screening, afterwards using measurement mat (Sensomative)HoursScreening, T1+, T2+, T3+, T4+PI, SP
Skin check performanceQuestioningTimes/weekT1, T2, T3, T4, T5/ToccPI[11]
SmokingQuestioningCigarettes/dayT1, T2, T3, T4, T5/ToccPI[47,51,55,57]
Spasticity lower extremitiesModified Ashworth ScaleScore from 0 to 4T1, (T2), (T3), (T4), (T5/Tocc)PI[2,48,63]
Spasticity upper extremitiesModified Ashworth ScaleScore from 0 to 4T1, (T2), (T3), (T4), (T5/Tocc)SP[2,48,63]
SR-PR performanceQuestioningTimes/hour and seconds/PRT1+, T2+, T3+, T4+PI
Transfer number/dayMeasurement mat (Sensomative)Times/dayT1+, T2+, T3+, T4+PI, SP[11,64]
Transfer qualityTransfer Assessment InstrumentScore from 0 to 10T1, (T2), (T3), (T4), (T5/Tocc)PI, SP[11,64,65,66]
WeightMeasurement on a wheelchair-accessible scale, measurement of wheelchair separately from participantkgT1, (T2), (T3), (T4), (T5/Tocc)PI, SP[11,12,22,48,50,55]
Wheelchair hip angleGoniometerDegreesT1, (T2), (T3), (T4), (T5/Tocc)PI[12]
Wheelchair shoulder positionAssessmentIn front of hip/above hip/behind hipT1, (T2), (T3), (T4), (T5/Tocc)SP[12]
Wheelchair cushion typeQuestioningCushion brand and modelT1, (T2), (T3), (T4), (T5/Tocc)PI[11,67]
Wheelchair mobilityWearable IMU sensor attached to wheelchair wheel (Axivity AX6, Axivity Ltd., Newcastle upon Tyne, UK)Distance covered (km/day), linear velocity of the wheelchair (km/h), number of pushes (pushes/day), duration of pushes (s/push), number of turns (turns/day), magnitude of turns (degrees/turn)T1+, T2+, T3+, T4+PI, SP[22,39]
Note. AIS = American Spinal Cord Injury (AISA) Impairment Scale; IMU = Inertial Measurement Unit; ISAFSCI = International Standards to Document Remaining Autonomic Function After Spinal Cord Injury; MVPA = Moderate-to-Vigorous Intensity Physical Activity; PI = pressure injuries; PR performance = pressure relief performance; RoM = range of motion; SP = shoulder pain; T1, T2, T3, T4, T5 = study visits; T1+, T2+, T3+, T4+ = measurement periods of three weeks; (T2), (T3), (T4), (T5/Tocc) = update, assessment only performed if necessary (changes since baseline measurement).

References

  1. Anthony, D.; Alosaimi, D.; Shiferaw, W.S.; Korsah, K.; Safari, R. Prevalence of pressure ulcers in africa: A systematic review and meta-analysis. J. Tissue Viability 2021, 30, 137–145. [Google Scholar] [CrossRef]
  2. Bossuyt, F.M.; Arnet, U.; Brinkhof, M.W.G.; Eriks-Hoogland, I.; Lay, V.; Muller, R.; Sunnaker, M.; Hinrichs, T. Shoulder pain in the Swiss spinal cord injury community: Prevalence and associated factors. Disabil. Rehabil. 2018, 40, 798–805. [Google Scholar] [CrossRef]
  3. Liampas, A.; Neophytou, P.; Sokratous, M.; Varrassi, G.; Ioannou, C.; Hadjigeorgiou, G.M.; Zis, P. Musculoskeletal pain due to wheelchair use: A systematic review and meta-analysis. Pain Ther. 2021, 10, 973–984. [Google Scholar] [CrossRef] [PubMed]
  4. Shiferaw, W.S.; Akalu, T.Y.; Mulugeta, H.; Aynalem, Y.A. The global burden of pressure ulcers among patients with spinal cord injury: A systematic review and meta-analysis. BMC Musculoskelet. Disord. 2020, 21, 334. [Google Scholar] [CrossRef]
  5. Richardson, A.; Samaranayaka, A.; Sullivan, M.; Derrett, S. Secondary health conditions and disability among people with spinal cord injury: A prospective cohort study. J. Spinal Cord Med. 2021, 44, 19–28. [Google Scholar] [CrossRef]
  6. Chen, H.L.; Cai, J.Y.; Du, L.; Shen, H.W.; Yu, H.R.; Song, Y.P.; Zha, M.L. Incidence of pressure injury in individuals with spinal cord injury: A systematic review and meta-analysis. J. Wound Ostomy Cont. Nurs. 2020, 47, 215–223. [Google Scholar] [CrossRef] [PubMed]
  7. Edsberg, L.E.; Black, J.M.; Goldberg, M.; McNichol, L.; Moore, L.; Sieggreen, M. Revised National Pressure Ulcer Advisory Panel pressure injury staging system: Revised pressure injury staging system. J. Wound Ostomy Cont. Nurs. 2016, 43, 585–597. [Google Scholar] [CrossRef]
  8. Vecin, N.M.; Gater, D.R. Pressure injuries and management after spinal cord injury. J. Pers. Med. 2022, 12, 1130. [Google Scholar] [CrossRef]
  9. Sprigle, S.; Sonenblum, S. Assessing evidence supporting redistribution of pressure for pressure ulcer prevention: A review. J. Rehabil. Res. Dev. 2011, 48, 203–213. [Google Scholar] [CrossRef]
  10. Najmanova, K.; Neuhauser, C.; Krebs, J.; Baumberger, M.; Schaefer, D.J.; Sailer, C.O.; Wettstein, R.; Scheel-Sailer, A. Risk factors for hospital acquired pressure injury in patients with spinal cord injury during first rehabilitation: Prospective cohort study. Spinal Cord 2022, 60, 45–52. [Google Scholar] [CrossRef]
  11. Benbow, M. Pressure ulcer prevention and pressure-relieving surfaces. Br. J. Nurs. 2008, 17, 830–835. [Google Scholar] [CrossRef] [PubMed]
  12. Dyson-Hudson, T.A.; Kirshblum, S.C. Shoulder pain in chronic spinal cord injury, Part I: Epidemiology, etiology, and pathomechanics. J. Spinal Cord Med. 2004, 27, 4–17. [Google Scholar] [CrossRef]
  13. Cao, Y.; Krause, J.S. The association between secondary health conditions and indirect costs after spinal cord injury. Spinal Cord 2021, 59, 306–310. [Google Scholar] [CrossRef]
  14. Dryden, D.M.; Saunders, L.D.; Rowe, B.H.; May, L.A.; Yiannakoulias, N.; Svenson, L.W.; Schopflocher, D.P.; Voaklander, D.C. Utilization of health services following spinal cord injury: A 6-year follow-up study. Spinal Cord 2004, 42, 513–525. [Google Scholar] [CrossRef]
  15. Gould, L.J.; Alderden, J.; Aslam, R.; Barbul, A.; Bogie, K.M.; El Masry, M.; Graves, L.Y.; White-Chu, E.F.; Ahmed, A.; Boanca, K.; et al. WHS guidelines for the treatment of pressure ulcers—2023 update. Wound Repair. Regen. 2024, 32, 6–33. [Google Scholar] [CrossRef] [PubMed]
  16. Young, D.L.; Shen, J.J.; Estocado, N.; Landers, M.R. Financial impact of improved pressure ulcer staging in the acute hospital with use of a new tool, the NE1 Wound Assessment Tool. Adv. Skin Wound Care 2012, 25, 158–166. [Google Scholar] [CrossRef] [PubMed]
  17. White, B.A.B.; Dea, N.; Street, J.T.; Cheng, C.L.; Rivers, C.S.; Attabib, N.; Kwon, B.K.; Fisher, C.G.; Dvorak, M.F. The economic burden of urinary tract infection and pressure ulceration in acute traumatic spinal cord injury admissions: Evidence for comparative economics and decision analytics from a matched case-control study. J. Neurotrauma 2017, 34, 2892–2900. [Google Scholar] [CrossRef]
  18. Smit, C.A.; Zwinkels, M.; van Dijk, T.; de Groot, S.; Stolwijk-Swuste, J.M.; Janssen, T.W. Gluteal blood flow and oxygenation during electrical stimulation-induced muscle activation versus pressure relief movements in wheelchair users with a spinal cord injury. Spinal Cord 2013, 51, 694–699. [Google Scholar] [CrossRef]
  19. Sonenblum, S.E.; Sprigle, S.H.; Martin, J.S. Everyday sitting behavior of full-time wheelchair users. J. Rehabil. Res. Dev. 2016, 53, 585–598. [Google Scholar] [CrossRef]
  20. European Pressure Ulcer Advisory Panel; National Pressure Ulcer Advisory Panel; Pan Pacific Pressure Injury Alliance. Prevention and Treatment of Pressure Ulcers: Quick Reference Guide, 2nd ed.; Cambridge Media: Osborne Park, WA, Australia, 2014. [Google Scholar]
  21. Sonenblum, S.E.; Vonk, T.E.; Janssen, T.W.; Sprigle, S.H. Effects of wheelchair cushions and pressure relief maneuvers on ischial interface pressure and blood flow in people with spinal cord injury. Arch. Phys. Med. Rehabil. 2014, 95, 1350–1357. [Google Scholar] [CrossRef]
  22. Arnet, U.; Boninger, M.L.; Cools, A.; Bossuyt, F.M. Effect of fatiguing wheelchair propulsion and weight relief lifts on subacromial space in wheelchair users. Front. Rehabil. Sci. 2022, 3, 849629. [Google Scholar] [CrossRef] [PubMed]
  23. van Drongelen, S.; van der Woude, L.H.; Janssen, T.W.; Angenot, E.L.; Chadwick, E.K.; Veeger, D.H. Glenohumeral contact forces and muscle forces evaluated in wheelchair-related activities of daily living in able-bodied subjects versus subjects with paraplegia and tetraplegia. Arch. Phys. Med. Rehabil. 2005, 86, 1434–1440. [Google Scholar] [CrossRef] [PubMed]
  24. Nawoczenski, D.A.; Clobes, S.M.; Gore, S.L.; Neu, J.L.; Olsen, J.E.; Borstad, J.D.; Ludewig, P.M. Three-dimensional shoulder kinematics during a pressure relief technique and wheelchair transfer. Arch. Phys. Med. Rehabil. 2003, 84, 1293–1300. [Google Scholar] [CrossRef]
  25. State Spinal Cord Injury Service. Spinal Seating Modules: Module 8—Pressure Management. Available online: https://aci.health.nsw.gov.au/networks/spinal-cord-injury/spinal-seating/module-8/recognizing-key-relationships-between-the-client-and-wheelchair#_ftn1 (accessed on 10 April 2025).
  26. Northwest Regional Spinal Cord Injury System. Spinal Cord Injury Model Systems Consumer Information: Skin Care & Pressure Sores. Available online: http://sci.washington.edu/info/pamphlets/msktc-pressure_relief.asp (accessed on 10 April 2025).
  27. Coggrave, M.J.; Rose, L.S. A specialist seating assessment clinic: Changing pressure relief practice. Spinal Cord 2003, 41, 692–695. [Google Scholar] [CrossRef]
  28. Schofield, R.; Porter-Armstrong, A.; Stinson, M. Reviewing the literature on the effectiveness of pressure relieving movements. Nurs. Res. Pract. 2013, 2013, 124095. [Google Scholar] [CrossRef]
  29. Sprigle, S.; Sonenblum, S.E.; Feng, C. Pressure redistributing in-seat movement activities by persons with spinal cord injury over multiple epochs. PLoS ONE 2019, 14, e0210978. [Google Scholar] [CrossRef]
  30. Hubli, M.; Zemp, R.; Albisser, U.; Camenzind, F.; Leonova, O.; Curt, A.; Taylor, W.R. Feedback improves compliance of pressure relief activities in wheelchair users with spinal cord injury. Spinal Cord 2021, 59, 175–184. [Google Scholar] [CrossRef]
  31. Chan, A.W.; Tetzlaff, J.M.; Altman, D.G.; Laupacis, A.; Gotzsche, P.C.; Krleza-Jeric, K.; Hrobjartsson, A.; Mann, H.; Dickersin, K.; Berlin, J.A.; et al. SPIRIT 2013 statement: Defining standard protocol items for clinical trials. Ann. Intern. Med. 2013, 158, 200–207. [Google Scholar] [CrossRef]
  32. Post, M.W.; Brinkhof, M.W.; von Elm, E.; Boldt, C.; Brach, M.; Fekete, C.; Eriks-Hoogland, I.; Curt, A.; Stucki, G.; SwiSCI Study Group. Design of the Swiss Spinal Cord Injury Cohort Study. Am. J. Phys. Med. Rehabil. 2011, 90, S5–S16. [Google Scholar] [CrossRef]
  33. Higgins, J.P.T.; Li, T.; Deeks, J.J. Chapter 6: Choosing effect measures and computing estimates of effect. In Cochrane Handbook for Systematic Reviews of Interventions Version 6.5; Higgins, J.P.T., Thomas, J., Chandler, J., Cumpston, M., Li, T., Page, M.J., Welch, V.A., Eds.; Cochrane Collaboration: London, UK, 2024; Available online: www.training.cochrane.org/handbook (accessed on 10 April 2025).
  34. Gross-Hemmi, M.H.; Gemperli, A.; Fekete, C.; Brach, M.; Schwegler, U.; Stucki, G. Methodology and study population of the second Swiss national community survey of functioning after spinal cord injury. Spinal Cord 2021, 59, 363–372. [Google Scholar] [CrossRef]
  35. Raghavan, P.; Raza, W.A.; Ahmed, Y.S.; Chamberlain, M.A. Prevalence of pressure sores in a community sample of spinal injury patients. Clin. Rehabil. 2003, 17, 879–884. [Google Scholar] [CrossRef] [PubMed]
  36. Scheel-Sailer, A.; Wyss, A.; Boldt, C.; Post, M.W.; Lay, V. Prevalence, location, grade of pressure ulcers and association with specific patient characteristics in adult spinal cord injury patients during the hospital stay: A prospective cohort study. Spinal Cord 2013, 51, 828–833. [Google Scholar] [CrossRef] [PubMed]
  37. Sprigle, S.; McNair, D.; Sonenblum, S. Pressure ulcer risk factors in persons with mobility-related disabilities. Adv. Skin Wound Care 2020, 33, 146–154. [Google Scholar] [CrossRef]
  38. Verschueren, J.H.; Post, M.W.; de Groot, S.; van der Woude, L.H.; van Asbeck, F.W.; Rol, M. Occurrence and predictors of pressure ulcers during primary in-patient spinal cord injury rehabilitation. Spinal Cord 2011, 49, 106–112. [Google Scholar] [CrossRef]
  39. de Vries, W.H.K.; van der Slikke, R.M.A.; van Dijk, M.P.; Arnet, U. Real-life wheelchair mobility metrics from IMUs. Sensors 2023, 23, 7174. [Google Scholar] [CrossRef]
  40. Curtis, K.A.; Roach, K.E.; Applegate, E.B.; Amar, T.; Benbow, C.S.; Genecco, T.D.; Gualano, J. Reliability and validity of the Wheelchair User’s Shoulder Pain Index (WUSPI). Paraplegia 1995, 33, 595–601. [Google Scholar] [CrossRef]
  41. Brosteanu, O.; Houben, P.; Ihrig, K.; Ohmann, C.; Paulus, U.; Pfistner, B.; Schwarz, G.; Strenge-Hesse, A.; Zettelmeyer, U. Risk analysis and risk adapted on-site monitoring in noncommercial clinical trials. Clin. Trials 2009, 6, 585–596. [Google Scholar] [CrossRef]
  42. Zemp, R.; Fliesser, M.; Wippert, P.M.; Taylor, W.R.; Lorenzetti, S. Occupational sitting behaviour and its relationship with back pain—A pilot study. Appl. Ergon. 2016, 56, 84–91. [Google Scholar] [CrossRef]
  43. Zemp, R.; Tanadini, M.; Pluss, S.; Schnuriger, K.; Singh, N.B.; Taylor, W.R.; Lorenzetti, S. Application of Machine Learning Approaches for Classifying Sitting Posture Based on Force and Acceleration Sensors. Biomed. Res. Int. 2016, 2016, 5978489. [Google Scholar] [CrossRef]
  44. Sterne, J.A.; White, I.R.; Carlin, J.B.; Spratt, M.; Royston, P.; Kenward, M.G.; Wood, A.M.; Carpenter, J.R. Multiple imputation for missing data in epidemiological and clinical research: Potential and pitfalls. BMJ 2009, 338, b2393. [Google Scholar] [CrossRef]
  45. Carpenter, J.R.; Smuk, M. Missing data: A statistical framework for practice. Biom. J. 2021, 63, 915–947. [Google Scholar] [CrossRef] [PubMed]
  46. National Pressure Injury Advisory Panel. NPUAP Pressure Injury Stages. Available online: https://cdn.ymaws.com/npiap.com/resource/resmgr/online_store/npiap_pressure_injury_stages.pdf (accessed on 10 April 2025).
  47. Gould, L.J.; Bohn, G.; Bryant, R.; Paine, T.; Couch, K.; Cowan, L.; McFarland, F.; Simman, R. Pressure ulcer summit 2018: An interdisciplinary approach to improve our understanding of the risk of pressure-induced tissue damage. Wound Repair Regen. 2019, 27, 497–508. [Google Scholar] [CrossRef]
  48. Hajhosseini, B.; Longaker, M.T.; Gurtner, G.C. Pressure Injury. Ann. Surg. 2020, 271, 671–679. [Google Scholar] [CrossRef]
  49. Kentar, Y.; Zastrow, R.; Bradley, H.; Brunner, M.; Pepke, W.; Bruckner, T.; Raiss, P.; Hug, A.; Almansour, H.; Akbar, M. Prevalence of upper extremity pain in a population of people with paraplegia. Spinal Cord 2018, 56, 695–703. [Google Scholar] [CrossRef] [PubMed]
  50. Schultz, A.; Bien, M.; Dumond, K.; Brown, K.; Myers, A. Etiology and incidence of pressure ulcers in surgical patients. AORN J. 1999, 70, 434–449. [Google Scholar] [CrossRef]
  51. Li, C.; DiPiro, N.D.; Cao, Y.; Szlachcic, Y.; Krause, J. The association between metabolic syndrome and pressure ulcers among individuals living with spinal cord injury. Spinal Cord 2016, 54, 967–972. [Google Scholar] [CrossRef]
  52. Bjelland, I.; Dahl, A.A.; Haug, T.T.; Neckelmann, D. The validity of the Hospital Anxiety and Depression Scale. An updated literature review. J. Psychosom. Res. 2002, 52, 69–77. [Google Scholar] [CrossRef]
  53. Wecht, J.M.; Krassioukov, A.V.; Alexander, M.; Handrakis, J.P.; McKenna, S.L.; Kennelly, M.; Trbovich, M.; Biering-Sorensen, F.; Burns, S.; Elliott, S.L.; et al. International Standards to document Autonomic Function following SCI (ISAFSCI): Second Edition. Top. Spinal Cord Inj. Rehabil. 2021, 27, 23–49. [Google Scholar] [CrossRef]
  54. Coleman, S.; Gorecki, C.; Nelson, E.A.; Closs, S.J.; Defloor, T.; Halfens, R.; Farrin, A.; Brown, J.; Schoonhoven, L.; Nixon, J. Patient risk factors for pressure ulcer development: Systematic review. Int. J. Nurs. Stud. 2013, 50, 974–1003. [Google Scholar] [CrossRef]
  55. Gould, L.J.; Olney, C.M.; Nichols, J.S.; Block, A.R.; Simon, R.M.; Guihan, M. Spinal cord injury survey to determine pressure ulcer vulnerability in the outpatient population. Med. Hypotheses 2014, 83, 552–558. [Google Scholar] [CrossRef]
  56. Fekete, C.; Eriks-Hoogland, I.; Baumberger, M.; Catz, A.; Itzkovich, M.; Luthi, H.; Post, M.W.; von Elm, E.; Wyss, A.; Brinkhof, M.W. Development and validation of a self-report version of the Spinal Cord Independence Measure (SCIM III). Spinal Cord 2013, 51, 40–47. [Google Scholar] [CrossRef] [PubMed]
  57. Li, C.; DiPiro, N.D.; Krause, J. A latent structural equation model of risk behaviors and pressure ulcer outcomes among people with spinal cord injury. Spinal Cord 2017, 55, 553–558. [Google Scholar] [CrossRef] [PubMed]
  58. Lewis, J.S. Rotator cuff tendinopathy: A model for the continuum of pathology and related management. Br. J. Sports Med. 2010, 44, 918–923. [Google Scholar] [CrossRef] [PubMed]
  59. Tokish, J.M.; Decker, M.J.; Ellis, H.B.; Torry, M.R.; Hawkins, R.J. The belly-press test for the physical examination of the subscapularis muscle: Electromyographic validation and comparison to the lift-off test. J. Shoulder Elbow Surg. 2003, 12, 427–430. [Google Scholar] [CrossRef]
  60. Hug, K.; Stumm, C.; Debecker, I.; Fellinghauer, C.S.; Peter, C.; Hund-Georgiadis, M. Self-efficacy and pressure ulcer prevention after spinal cord injury-results from a nationwide community survey in Switzerland (SwiSCI). PM&R 2018, 10, 573–586. [Google Scholar] [CrossRef]
  61. King, R.B.; Champion, V.L.; Chen, D.; Gittler, M.S.; Heinemann, A.W.; Bode, R.K.; Semik, P. Development of a measure of skin care belief scales for persons with spinal cord injury. Arch. Phys. Med. Rehabil. 2012, 93, 1814–1821. [Google Scholar] [CrossRef]
  62. Lazić, M.; Jovanović, V.; Gavrilov-Jerković, V. The general self-efficacy scale: New evidence of structural validity, measurement invariance, and predictive properties in relationship to subjective well-being in Serbian samples. Curr. Psychol. 2021, 40, 699–710. [Google Scholar] [CrossRef]
  63. Meseguer-Henarejos, A.B.; Sanchez-Meca, J.; Lopez-Pina, J.A.; Carles-Hernandez, R. Inter- and intra-rater reliability of the Modified Ashworth Scale: A systematic review and meta-analysis. Eur. J. Phys. Rehabil. Med. 2018, 54, 576–590. [Google Scholar] [CrossRef]
  64. Gagnon, D.; Nadeau, S.; Noreau, L.; Dehail, P.; Piotte, F. Comparison of peak shoulder and elbow mechanical loads during weight-relief lifts and sitting pivot transfers among manual wheelchair users with spinal cord injury. J. Rehabil. Res. Dev. 2008, 45, 863–873. [Google Scholar] [CrossRef]
  65. Hogaboom, N.S.; Worobey, L.A.; Boninger, M.L. Transfer technique is associated with shoulder pain and pathology in people with spinal cord injury: A cross-sectional investigation. Arch. Phys. Med. Rehabil. 2016, 97, 1770–1776. [Google Scholar] [CrossRef]
  66. Worobey, L.A.; Zigler, C.K.; Huzinec, R.; Rigot, S.K.; Sung, J.; Rice, L.A. Reliability and validity of the revised Transfer Assessment Instrument. Top. Spinal Cord Inj. Rehabil. 2018, 24, 217–226. [Google Scholar] [CrossRef] [PubMed]
  67. Ong, B.; Wilson, J.R.; Henzel, M.K. Management of the patient with chronic spinal cord injury. Med. Clin. N. Am. 2020, 104, 263–278. [Google Scholar] [CrossRef] [PubMed]
Figure 1. Study timeline. T1 to T5/Tocc = timepoints for assessment of confounders, three months apart; T1+ to T4+ = measurement periods of three weeks (continuous assessment of pressure relief performance and weekly assessment of shoulder pain) directly after T1 to T4.
Figure 1. Study timeline. T1 to T5/Tocc = timepoints for assessment of confounders, three months apart; T1+ to T4+ = measurement periods of three weeks (continuous assessment of pressure relief performance and weekly assessment of shoulder pain) directly after T1 to T4.
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Figure 2. Calculation of the minimal sample size using Cox proportional hazards modelling. The x-axis indicates the hazard ratio (Δ) for the event of a pressure injury owing to differences in pressure relief performance. Presuming a population-average, one-year probability for pressure injury (event of interest) of 0.3, and conventionally accepting a power (1 − β) of 0.8 and a significance level (α) of 0.05, a minimal sample size of 60 participants is needed to detect an empirically plausible hazard ratio of 3.2 or higher.
Figure 2. Calculation of the minimal sample size using Cox proportional hazards modelling. The x-axis indicates the hazard ratio (Δ) for the event of a pressure injury owing to differences in pressure relief performance. Presuming a population-average, one-year probability for pressure injury (event of interest) of 0.3, and conventionally accepting a power (1 − β) of 0.8 and a significance level (α) of 0.05, a minimal sample size of 60 participants is needed to detect an empirically plausible hazard ratio of 3.2 or higher.
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Figure 3. Pressure measurement mat.
Figure 3. Pressure measurement mat.
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Figure 4. (a) Inertial measurement unit and plastic case; (b) installed setup.
Figure 4. (a) Inertial measurement unit and plastic case; (b) installed setup.
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Table 1. Eligibility criteria assessed during the screening visit.
Table 1. Eligibility criteria assessed during the screening visit.
Inclusion CriteriaExclusion Criteria
  • Persons with a complete spinal cord injury (AIS A)
  • Age ≥ 18 years
  • Time since injury ≥ 5 years
  • Main mode of mobility: manual wheelchair
  • Score of 1 or 2 in the SCIM-SR item “Mobility for Moderate Distances”: needs electric wheelchair or partial assistance to operate manual wheelchair (1) or moves independently in manual wheelchair (2)
  • Ability to perform pressure relief independently or with the aid of the wheelchair or a table
  • Living in Switzerland
  • Total daily sitting time < 8 h
  • Need of a specialised assistive device for performing pressure relief
  • Current hospitalisation
  • Current pressure injury
  • Pregnancy (anamnestic)
Note: AIS = American Spinal Injury Association Impairment Scale, SCIM-SR = Spinal Cord Independence Measure Self-Report.
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MDPI and ACS Style

Schürch, Y.; Hertig-Godeschalk, A.; Eriks-Hoogland, I.; Scheel-Sailer, A.; Brinkhof, M.W.G.; Arnet, U. Investigating the Impact of Pressure Relief Performance on the Occurrence of Pressure Injuries and Shoulder Pain in Wheelchair Users with Spinal Cord Injury (PRperf Study): Study Protocol for a Prospective Observational Study. Methods Protoc. 2025, 8, 62. https://doi.org/10.3390/mps8030062

AMA Style

Schürch Y, Hertig-Godeschalk A, Eriks-Hoogland I, Scheel-Sailer A, Brinkhof MWG, Arnet U. Investigating the Impact of Pressure Relief Performance on the Occurrence of Pressure Injuries and Shoulder Pain in Wheelchair Users with Spinal Cord Injury (PRperf Study): Study Protocol for a Prospective Observational Study. Methods and Protocols. 2025; 8(3):62. https://doi.org/10.3390/mps8030062

Chicago/Turabian Style

Schürch, Yannik, Anneke Hertig-Godeschalk, Inge Eriks-Hoogland, Anke Scheel-Sailer, Martin W. G. Brinkhof, and Ursina Arnet. 2025. "Investigating the Impact of Pressure Relief Performance on the Occurrence of Pressure Injuries and Shoulder Pain in Wheelchair Users with Spinal Cord Injury (PRperf Study): Study Protocol for a Prospective Observational Study" Methods and Protocols 8, no. 3: 62. https://doi.org/10.3390/mps8030062

APA Style

Schürch, Y., Hertig-Godeschalk, A., Eriks-Hoogland, I., Scheel-Sailer, A., Brinkhof, M. W. G., & Arnet, U. (2025). Investigating the Impact of Pressure Relief Performance on the Occurrence of Pressure Injuries and Shoulder Pain in Wheelchair Users with Spinal Cord Injury (PRperf Study): Study Protocol for a Prospective Observational Study. Methods and Protocols, 8(3), 62. https://doi.org/10.3390/mps8030062

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