Physical Rehabilitation Programs for Bedridden Patients with Prolonged Immobility: A Scoping Review

Bedridden patients usually stay in bed for long periods, presenting several problems caused by immobility, leading to a long recovery process. Thus, identifying physical rehabilitation programs for bedridden patients with prolonged immobility requires urgent research. Therefore, this scoping review aimed to map existing physical rehabilitation programs for bedridden patients with prolonged immobility, the rehabilitation domains, the devices used, the parameters accessed, and the context in which these programs were performed. This scoping review, guided by the Joanna Briggs Institute’s (JBI) methodology and conducted in different databases (including grey literature), identified 475 articles, of which 27 were included in this review. The observed contexts included research institutes, hospitals, rehabilitation units, nursing homes, long-term units, and palliative care units. Most of the programs were directed to the musculoskeletal domain, predominantly toward the lower limbs. The devices used included lower limb mobilization, electrical stimulation, inclined planes, and cycle ergometers. Most of the evaluated parameters were musculoskeletal, cardiorespiratory, or vital signs. The variability of the programs, domains, devices and parameters found in this scoping review revealed no uniformity, a consequence of the personalization and individualization of care, which makes the development of a standard intervention program challenging.


Introduction
The developed societies currently face a severe demographic change: the world is aging at an unprecedented rate [1,2]. In 2050, the world population over 65 years old will near 1500 million people, about 22 percent of the world population [3]. With the increase in the average human lifespan, the number of older persons with mobility impairment, namely bedridden patients, is growing. In addition, bedridden patients caused by accidents and An initial limited search was undertaken on MEDLINE (via PubMed) and CINAHL Complete (via EBSCOhost) to identify articles on the topic. Consequently, the text words/ expressions in the titles and abstracts of relevant articles and the index terms used to describe the articles were used to develop a complete search strategy across all the databases. Additionally, the reference list of all included papers was hand-searched for additional studies. The inclusion criteria of this scoping review were based on the "PCC" mnemonic: Population, Concept, and Context. Accordingly, this review considered studies: that included programs for bedridden patients with prolonged immobility (Population) that explored physical rehabilitation programs (Concept) conducted in any setting independently of the country of the study (Context). We also considered quantitative, qualitative, and mixed methods study designs for inclusion. Additionally, all types of systematic reviews were considered for inclusion independently of the publication date. The search strategy used in this scoping review can be seen in Table 1.

Data Extraction
All the records identified through database searching were retrieved and stored using Mendeley ® V1.19.8 software (Mendeley Ltd., Elsevier, The Netherlands), and any duplications were removed. All identified articles were accessed for relevance according to the title and abstract. The full text of the selected citations was assessed in detail against the inclusion criteria by two independent reviewers. The data were extracted from the articles and included in the review independently by two reviewers, using a data extraction table aligned with the objectives and research questions. The data extracted included: the author, year and country of the study, population characteristics, physical rehabilitation programs, accessed parameters, setting, and devices used. In the case of missing data, the study authors were contacted. Any disagreements regarding what data was relevant for extraction were resolved through discussion or with a third reviewer. CINAHL Complete-searched on 8 July 2021: 37 results (TI rehab* OR AB rehab* OR TI exercise* OR AB exercise* OR ((TI physical OR AB physical) N1 (TI activit* OR AB activit*)) OR (MH "Therapeutic Exercise") OR (MH "Physical Activity") OR (MH "Exercise") OR (MH "Rehabilitation")) AND (TI bedridden OR AB bedridden OR (MH "Bedridden Persons")) Limiters-Exclude MEDLINE records; Language: English, Portuguese, Spanish Cochrane Central Register of Controlled Trials-searched on 8 July 2021: 50 results (TI rehab* OR AB rehab* OR TI exercise* OR AB exercise* OR ((TI physical OR AB physical) N1 (TI activit* OR AB activit*))) AND (TI bedridden OR AB bedridden) Cochrane Database of Systematic Reviews-searched on 8 July 2021: 1 result (TI rehab* OR AB rehab* OR TI exercise* OR AB exercise* OR ((TI physical OR AB physical) N1 (TI activit* OR AB activit*))) AND (TI bedridden OR AB bedridden) Scopus-searched on 8 July 2021: 93 results ((TITLE-ABS (rehabilitation) OR TITLE-ABS (exercise*)) AND (TITLE-ABS (bedridden))) AND NOT ((PMID (1*) OR PMID (2*) OR PMID (3*) OR PMID (4*) OR PMID (5*) OR PMID (6*) OR PMID (7*) OR PMID (8*) OR PMID (9*))) AND (LIMIT-TO (LANGUAGE, "English") OR LIMIT-TO (LANGUAGE, "Portuguese") OR LIMIT-TO (LANGUAGE, "Spanish")) Scielo-searched on 8 July 2021: 4 results (ti:(rehabilitation OR exercise*)) OR (ab:(rehabilitation OR exercise*)) AND (ti:(bedridden)) OR (ab:(bedridden)) SPORTDiscus with Full Text-searched on 8 July 2021: 11 results (ti:(rehabilitation OR exercise)) OR (ab:(rehabilitation OR exercise)) AND (ti:(bedridden)) OR (ab:(bedridden)) Filters: English, Portuguese, Spanish Rehabilitation & Sports Medicine Source-searched on 8 July 2021: 11 results (ti:(rehabilitation OR exercise)) OR (ab:(rehabilitation OR exercise)) AND (ti:(bedridden)) OR (ab:(bedridden)) Filters: English, Portuguese, Spanish

Context
Most studies were performed in research institutes (n = 10) and hospital contexts (n = 10), followed on rehabilitation units (n = 3), welfare or nursing homes (n = 2), one long-term care facility (LTC) and one hospice. Studies performed in hospital context involved multiple conditions such as multi-trauma [54], hip fracture [45], sarcopenia [53], older patients with unspecified conditions [30,41,49], patients with COPD mechanical ventilated [42], or other mechanical ventilated patients [43], namely in the ICU [42,51]. Rehabilitation units involved patients with stroke [31], patients with multiple sclerosis [44], and one patient with head trauma caused by a car accident [38]. LTC facilities treated bedridden older stroke survivors [39]. In the welfare home, the programs were applied to bedridden patients with disuse syndrome [35] and in nursing homes for bedridden patients with multiple conditions but mainly stroke [50]. Finally, one study described a rehabilitation program in a hospice setting for palliative patients with fewer than three months' life expectancy (mainly due to cancer diagnosis) [33]. Alkner et al. [28] 2004, Sweden Seventeen healthy subjects (26-41 years). Study subjects were divided into two groups: with (8) or without (9) resistance exercise The training was performed in the 6 • head-down tilt position. Study subjects performed four sets of 7 repetitions of supine squat and 14 repetitions of calf press every third day using a gravity-independent flywheel ergometer for 29 days; 2 min of rest was allowed between sets and 5 min between exercises Quadriceps and triceps muscle volume using MRI (before and after bed rest). EMG, Peak force, power, work velocity, and minimum joint angle (for each repetition)

Research institute
Gravityindependent flywheel ergometer, Benjamin et al. [29] 2009, USA One healthy man (69 years) The study subject used a newly designed bodysuit that applied precise loads to specific body parts Artificial gravity force

Research institute Bodysuit
Blanc-Bisson et al. [30]  Exercise testing and training were conducted using supine leg press and supine calf press exercise; Intensity (eccentric): 0% (concentric-only training), 33, 66, 100, or 138% of the concentric load. The program was performed 3 days per week over 12 weeks: 3 weeks of pre-testing, 8 weeks of training, and 1 week of post-testing, Pre-and post-training whole body, lumbar spine, and hip bone mineral density. Whole-body lean tissue mass.
Urine and blood markers of bone metabolism.

Research institute
Agaton Fitness System (Agaton Fitness AB, Boden, Sweden) Golčić et al. [33] 2018, Croatia Five hundred and thirty-six palliative patients with a life expectancy of fewer than 3 months (mainly cancer diagnosis), 71.77 ± 11.13 years. An approximate number of females (50.56%) and males.
The program consisted of active, actively assisted, and passive positioning exercises. Active exercises included the ability to move at least one of the arms or the legs against gravity. The exercises were considered actively assisted if the patients could start and perform the motion but were unable to complete the normal range of motion. Passive exercises consisted of stretching (5 to 10 repetitions) and performing ROM in at least all large joints of the extremities.
Manual-muscle test and performance score.

Hospice Unspecified
Ino et al. [34] 2009, Japan Ten healthy subjects (20 to 80 years) Subjects' toe joints were subjected to bending and stretching motions for 2 min, keeping the subjects in a supine position for 5 to 10 min Lower limb blood flow

Research institute
Device for passive mobilization of toe joints  (40) Comprehensive rehabilitation nursing intervention was employed as follows: once a day, 50 min, 5 times a week and consisted of: Uyghur medicine; hand micro-vibration therapy, and training combined with education through a 20 min video once per week.
ROM of the hip joint, knee joint, and ankle joint.

Welfare home Unspecified
Pittaccio et al. [36] 2013, Italy Four healthy subjects (2 male; 2 female) This program consisted of rest, active, passive, and assisted conditions for 5 min. Rest: the subject laid with the leg positioned on the leg rest of the mobilizer. Active: the subject performed a voluntary movement of the ankle, alternating 7 s of dorsiflexion hold to 30 s of relaxation. Passive and assisted conditions were performed with the Toe-Up! The device was set to produce cycles of 30 • dorsiflexion (7 s) and relaxation towards plantar flexion in 30 s. In the passive condition: Toe-Up performed a continuous passive motion (CPM) to the subject's ankle, whereas in the assisted condition, the subject was instructed to follow the CPM, collaborating actively in the dorsiflexion promoted by the device Brain activity (EEG and NIRS in 4 different conditions: rest, active dorsiflexion of the ankle, passive mobilization of the ankle, and assisted motion of the same joint

Research institute
Toe-Up! An electromechanical mobilizer for the ankle joint Shimizu et al. [37] 2017, Japan Eight healthy subjects (5M; 3F); 21.6 ± 2.3 years, (19-25 years), Patients had no history (or risk factors) for deep vein thrombosis or lower limb operation The participants performed 1-min leg exercise apparatus (LEX) exercises in three modes: (1) rapid single ankle motion (maximum active ankle dorsiflexion/plantarflexion at a rate of 60 cycles/min); (2) slow single ankle motion (maximum active ankle dorsiflexion/plantarflexion at a rate of 30 cycles/min); and (3) slow combined leg motion (active ankle dorsiflexion/plantarflexion and subtalar eversion/inversion at a rate of 30 cycles/min, with natural knee extension/flexion, hip/extension, and hip internal/external rotation).
Venous flow volume and velocity in the femoral vein at 1, 10, 20, and 30 min postexercise. These measurements were repeated three times for each participant,

Research institute
The LEX is a portable apparatus that enables patients to move their legs while supine.

Talar et al. [38] 2002, Poland
Twenty-eight-yearold male bedridden who suffered severe closed head injuries in an automobile accident and was in a comatose state for more than two months (GCS score of 5).
Physiotherapy was started with the patient still in comatose as follows: hydrotherapy, physical stimulation, including interference current (0.10 and 0.100 amps for 10 min, 6 times daily), low-power magnetic stimulation (15 min, 6 times daily), scanning laser (trunk and limbs, power 2J, 10 min, 6 times daily); manual massage of the trunk and limbs (30 min, 4-5 times per week). Kinesitherapy was initiated to restore locomotion after the patient awakened from the coma.  The "upper-body yoga" training was as follows: with closed eyes, the patient concentrated on breathing to inhale slowly and deeply through one's nostrils, to raise his/her abdomen until the lung was fully expanded. Then, exhale completely through one's mouth with a sound of "a~~" 10 times. Additionally, the patient rotated all joints of the upper limbs during a 1-min warm-up period. In the following phase, the patients inhaled deeply and raised one of their arms slowly to 180 • from the front of the body, breathing quietly 3-5 times and exhaling completely with arms facing backward. Then, lean toward the left or right and breathe quietly 3-5 times before exhaling completely with arms facing backward. Then Inhale and exhale while simultaneously bending the elbows and rotating the shoulder joints as much as possible. In the final phase, the patient closes one's eyes and breathes in and out quietly with his/her hands placed on the abdomen to relax and meditate for 3 min, followed by two quick and forceful breaths using the sound of "ha~". The program was performed 2 times/day, 7 days/week FVC/predicted value (FVC%), peak cough flow, BI, the incidence of pneumonia, rates of right skills, and inclination. Patients were tested in a 30 • supine position on the day of admission (T1) after 7 days of training (T2) and 4 weeks after surgery (T3).

Ten healthy participants
The study consisted of four different study protocols. (1) subjects were tilted to the maximum tilt angle of 71 • and then to 40 • with a 3 min supine period in between. In a second step, the same experiment was conducted at 60 • instead of 71 • (2 and 3) both protocols were conducted at = {20 • , 40 • , 60 • } of tilt (three experiments per protocol) with or without FES, the FES frequency was set to 40 Hz. FES pulse was bipolar and biphasic with a width of 300 µs, and its amplitude could be varied between a minimum and a maximum (between 7 and 30 mA) (4). A 5-min synchronized stepping with minimum FES input was applied (uFES = 0, i.e., IMIN) followed by a 5-min interval of maximum FES input (uFES = 1, i.e., 0.8IMAX) and a 5-min period during which the amplitude was set back to the minimum current strength. Friedl-Werner et al. [47], 2020, Germany Twenty-three young, healthy men participants (29 ± 6 years) completed the study; 11 participants were randomly assigned to a high-intensity interval training (TRAIN) The exercise training was performed in a supine position. Four different training sessions consisting of varying numbers of countermovement jumps and hops were designed and applied to TRAIN 5 to 6 training sessions per week for 60 days. The total training duration of one session did not exceed more than 17 min using an average training load between 80% and 90% of the body weight.
Memory performance and brain regions involved using MRI and functional magnetic resonance imaging (fMRI) The QG and DG patients received conventional physical therapy once a day, plus a daily electrical stimulation session from the first day of randomization until ICU discharge. For the NMES of the quadriceps, the following parameters were used: Aussie current, synchronized impulse at a frequency of 50 Hz, 1 s pulse increase period, 8 s "on" (muscle contraction) period, 1 s pulse decrease period, and 30 s "off" (disconnection) period. For the NMES of the diaphragm, the following parameters were used: Aussie current, synchronized impulse at a frequency of 30 Hz, 1 s pulse increase period, 1 s "on" (muscle contraction) period, 1 s pulse decrease period, and 20 s "off" (disconnection) period. Each session was performed for 45 min at intensities that produced visible contractions.   [53] 2021, Japan

Research institute Unspecified
Seventy-year-old man bedridden man with sarcopenia developed as a postoperative complication The patient was treated by initiating a 6-month-long Nutrition Support Team intervention that combined nutrition, exercise therapy, and pharmacotherapy. Priority was given to patient mobilization, the balance of energy intake and expenditure, prevention of complications associated with bed rest, and prevention of the progression of generalized deconditioning. Upper body muscle training was started 5 days a week for 20 min. Lower-limb muscle training was initiated to prevent the loss of skeletal muscle.

Hospital Unspecified
Bouman et al. [54] 2008, The Netherlands One hundred and thirty-two multi-trauma patients admitted to one of the Accident and Emergency Departments (A&E) participating hospitals are included.
Intervention group: Phase 1; There were 10 sessions per week of 30 min each. In addition, fitness, gymnastics, table tennis, swimming, bowling, hand bike, wheelchair training, and archery are given. There were 2-3 sessions per week for each treatment modality of 60 min each. Phase 2: new treatment aims were added by the physiotherapist. These might include a gradual individual weight-bearing scheme, coordination training, and functional training. There were 7 therapy sessions per week of 30 min. In addition, fitness, gymnastics, table tennis, swimming, rowing, cycling, and archery are given. This is offered in 2-4 sessions per week for each treatment modality of 60 min each.

Programs and Domains
Most rehabilitation programs were directed to the musculoskeletal domain (n = 14). The other seven were directed to the cardiorespiratory domain and six to mixed/other domains. Most of the programs included in this scoping were applied only to lower limbs [28,30,32,36,37,40,41], also including [34], which only focused on toe joints. On the other hand, two studies [33,39] worked on both upper and lower limbs, and three studies [29,31,38] worked on the upper and lower body. Regarding the programs in the cardiorespiratory domain, three studies [42,44,45] mainly focused on respiratory rehabilitation: one [46] was primarily cardiovascular, whereas three [43,47,48] worked on both the respiratory and cardiovascular systems. The other six [49][50][51][52][53][54] were classified as mixed or other domains because multiple domains were present, and the programs were not explicit or focused on other rehabilitation domains, such as [53], which combined nutrition, exercise, and pharmacotherapy. Given its variability from study to study, and that not all studies have this information, the aspects related to the duration of the study and sessions: frequency, intensity, and progressivity, are presented in Table 2.

Devices
More than half (n = 17;~63%) of the above-described rehabilitation programs used rehabilitation devices. Of those devices, 11 were commercial devices, and the remain-ing 6 were prototypes. In the musculoskeletal programs, devices of different nature were used. Four studies [28,32,36,37] used devices for lower limb mobilization with different typologies (flywheel ergometer, leg press, and ankle or leg mobilizer), whereas one [40] used elastic bands, and [34] used a device for passive mobilization of toe joints. Devices for electrical stimulation were also widely used in the musculoskeletal [31,38,41], cardiorespiratory [42,46,48], and other/mixed domains [51]. Tilt tables for verticalization were also used in both musculoskeletal [31], cardiorespiratory [46], and mixed domains [49]. Two studies [31,46] used the commercial ERIGO tilt table, whereas the brand of this device used in one of the studies [49] was not specified. In the cardiorespiratory domain, the cycle ergometer was also common [43,48].

Clinical Parameters
A huge variety of parameters were accessed in the selected studies of this scoping to access the efficacy and safety of the above-described rehabilitation programs as the devices used in these programs. Most of the evaluated parameters were musculoskeletal, cardiorespiratory, or vital signs. In the musculoskeletal domain, the principal parameters accessed were muscular volume (using MRI) [28]. muscle strength [31,33,51] (mainly using the MRC scale), handgrip strength (using a dynamometer) [30], and force power (using a load cell) [28]. Still, in this domain, range of motion (ROM) [35,41], joint angular velocity [28], and angle measures [39] were also evaluated. Other techniques, such as dual-energy X-ray absorptiometry to measure bone mineral density [32] and EMG [28], were used.

Discussion
This scoping review mapped the different rehabilitation programs for bedridden patients described in 27 primary studies elaborated between 1999 and 2020, specifically including the domains studied, devices used, parameters accessed, and the context in which these programs were performed.

Context
Regarding the context, we observed that a large number of studies were performed in research institutes with healthy controls; thus, at the time of publication of these studies, the respective programs were not yet implemented in a clinical context. On the other hand, this also demonstrates the importance of performing preclinical and clinical studies with healthy individuals [55,56] to access the rehabilitation program's safety, since bedridden persons are often in a great state of fragility with a considerable variety of diseases and comorbidities [13,14]. A large number of studies were also performed in a hospital context. In this context, we observed that programs were applied to people with very different diseases (from hip fracture to stroke). On the other hand, other studies in the hospital context [30,41] and welfare/nursing homes [35,50] included patients (mostly older) with disuse syndrome, irrespective of the underlying cause [12,16]. Two studies [42,51] were specifically applied in the ICU context, demonstrating the importance of rehabilitation in intensive care to be performed as soon as possible [57,58]. Since rehabilitation is a continuous process [59], it can be started in the hospital but continued in rehabilitation centers and LTC, as observed in [31,38,39,44]. We also noticed a lack of studies on rehabilitation programs applied at home, possibly due to some barriers to implementing rehabilitation programs at home [60,61].

Domains
In this scoping review, we observed that most of the programs were directed to the musculoskeletal domain and, more specifically, the lower limbs. A lack of motor ability in the lower extremity affects walking ability balance and increases the risk of a fall [62]; on the other hand, it is the primary determinant of an independent and productive life and ADL [39,62]. Regarding the programs in the cardiorespiratory domain, two studies mainly focused on respiratory rehabilitation in ventilated persons [42,43]. This is especially important in this time of COVID-19 due to the number of persons that must be mechanically ventilated. Siddiq et al. [57] conducted a scoping review based on 40 recent publications demonstrating pulmonary rehabilitation's importance. In this article, Siddiq et al. argued that survivors weaned from mechanical ventilation are at a higher risk of developing post-intensive care syndrome and that respiratory rehabilitation should be started at the earliest possible opportunity [57]. However, we must stress that persons admitted to ICU due to COVID-19 or other causes will also need musculoskeletal rehabilitation since people who stay in the ICU are also at risk of developing post-intensive care syndromes, which are defined as "physical, cognition, and mental impairments that occur during ICU stay, after ICU discharge or hospital discharge, as well as in the long-term follow up of ICU patients" [63]. Indeed, the programs classified as mixed domains in Table 2 demonstrate the need in certain cases of rehabilitation that comprise different domains.

Devices
Evidence shows us how devices can be an essential complement to the care provided to bedridden users [31,41,48,64]. In fact, in this scoping review, more than 60% of the included studies used devices as a compliment. Of those, 11 were commercial, and the remaining 6 were prototypes. Thus, although professionals already use commercial devices, an investment in the development of new devices adjusted to the population's specific needs continues to be necessary. These devices are intended to fill gaps to which existing devices cannot yet respond [64]. In this scoping review, we also found that studies in the aerospatial scope [28,29] can be transported to the reality of clinical practice, even though their use was in a different scope. These studies focus on muscle and bone loss, which is a reality observed in long-duration missions in orbit and bedridden patients.

Parameters
This study observed a significant variability of parameters used to evaluate the implemented programs. The use of different parameters is often due to the study's specific objectives, the contexts where they are implemented, the specificities of the population being studied, and the available resources. It is important to emphasize the adequacy of using the selected parameters concerning what is intended to be evaluated. However, the significant variability of the evaluated parameters may severely impair study comparison. This can pose a challenge for the development of, for example, systematic reviews of effectiveness, as there is no homogeneity between studies to carry out a meta-analysis [65]. The parameters most used in the different studies concern vital signs, namely the heart and the respiratory rates. Their use is essential for monitoring the safety of studies that focus on interventions for bedridden patients. Another observed aspect was the absence of specific information regarding muscular and osteoarticular risks, specifically in the control of joint stability during movement, a relevant aspect, especially when talking about complementary/robotic devices [66].

Limitations
In this scoping review, we subdivided the programs into musculoskeletal and cardiorespiratory domains. However, the line that separates them can be thin, because programs directed to the musculoskeletal domain can also benefit the cardiorespiratory domain and vice versa. Another limitation was that some studies did not present part of the information we intended to map, such as a complete characterization of the population, rehabilitation programs, or devices used, making it difficult to obtain all the information intended from the studies individually. Despite this limitation, we tried to extract as much information as possible from different studies to map all the available evidence. Another potential limitation of this scoping review was that only studies published in English, Portuguese, and Spanish were included. Articles published in other languages may potentially add information to the results of this review. Furthermore, since the objective of this scoping review was to map the physical rehabilitation programs for bedridden patients with prolonged immobility, no rating of the methodological quality was used. Although a critical appraisal of the included studies was not evaluated, since it was not relevant for the scoping review, some limitations were reported to provide valuable information to future research studies/systematic reviews.

Conclusions
To date, no previous scoping reviews addressing this purpose have been found. Therefore, this scoping review constitutes a valuable starting point for analyzing and systematizing the rehabilitation programs used for bedridden patients. Additionally, which devices were used, the implementation context and the parameters accessed were analyzed.
There is a great diversity of programs with different structures and variability in both devices and parameters to be evaluated. This review revealed no standardization of these components, making developing a standard intervention program challenging. This occurs since the programs and their components are adjusted to the specificities of the population under study, requiring individualization to meet the individual needs of specific patients. According to this evidence, rehabilitation treatment can improve independence in patients with immobilization syndrome, irrespective of the underlying cause, as described previously by Bocciogne et al. [49].
Mapping the evidence about physical rehabilitation programs for bedridden patients with prolonged immobility contributes to understanding this phenomenon, helping health professionals and stakeholders develop more adjusted programs and which parameters should be considered. Therefore, this mapping contributed to the identification of relevant issues to help advance evidence-based rehabilitation interventions, construct knowledge, identify gaps, and inform systematic reviews. Funding: This research was co-financed by the European Regional Development Fund (ERDF) through the partnership agreement Portugal 2020-Operational Programme for Competitiveness and Internationalization (COMPETE2020) under the project POCI-01-0247-FEDER-047087 ABLEFIT: Desenvolvimento de um Sistema avançado para Reabilitação.

Institutional Review Board Statement: Not applicable.
Informed Consent Statement: Not applicable.