Search Results (15)

Background: Knee pain, proprioceptive deficits, and muscle weakness brought about by articular degeneration in knee osteoarthritis (OA) can cause postural instability and gait asymmetry. Arm swing plays a major role in balance control during human walking. However, few studies have examined the arm movement and gait stability in knee OA. Therefore, the purpose of this study is to investigate the gait asymmetry in upper and lower limb movement and to understand the overall movement pattern during walking in people with knee osteoarthritis. Methods: Thirty-five people with knee OA and twenty-four age-matched controls were enrolled in this study. The arm swing amplitude, gait biomechanics, and spatiotemporal parameters during walking were measured using a Vicon motion capture system incorporating two AMTI force plates. The differences between the knee OA and control groups were analyzed using independent t-tests. Results: The knee OA patients walked with a slower, smaller step and lower arm swing amplitude. The asymmetries of step time, foot progression angle, and total arm swing amplitude were significantly greater in the knee OA group than in the controls (p < 0.05). There was no significant difference in the mean value of step width and the foot progression angle and the asymmetry of step length and the knee adduction moment between the groups. Conclusions: This study demonstrates that the pathological changes in the lower limbs in knee OA are intrinsically reflected in the upper limbs through diagonal coordination. Asymmetry of arm swing and foot progression angle may be key for understanding OA-related instability. Full article

As neuromuscular performance assessment has become a fundamental component of athlete monitoring, ensuring strong measurement reliability is essential for supporting accurate data-driven decision-making. Thus, the purpose of this study was twofold: (i) to examine the reliability of countermovement vertical jump (CMJ) force-time metrics obtained using a portable force plate system (Hawkin Dynamics) and (ii) to determine whether absolute and relative reliability scores differ between well-trained individuals (i.e., athletes) and those less familiar with CMJ force-plate testing (i.e., non-athletes). Seventy-four participants volunteered to take part in this investigation, of whom thirty-nine were NCAA Division-I baseball and track-and-field athletes and thirty-five age-matched non-athletes with no prior CMJ testing experience on force plates. After performing a standardized dynamic warm-up, participants performed three CMJs without arm swing while standing on a dual uniaxial force plate system sampling at 1000 Hz. Each jump trial was separated by a 30 s rest interval. Absolute and relative reliability were assessed using the coefficient of variation (CV) and intraclass correlation coefficient (ICC), respectively. The results revealed that 75% of the variables demonstrated excellent reliability. Specifically, absolute (CV < 10%) and relative (ICC > 0.750) reliability values were good to excellent for most force-time metrics of interest, including braking and propulsive phase duration, peak braking force, average propulsive power, reactive strength index-modified, countermovement depth, and jump height. In contrast, average and peak landing force and inter-limb asymmetry measures during the braking and propulsive phases displayed moderate to good reliability, whereas asymmetry-related variables during the landing phase exhibited poor reliability. In addition, athletes demonstrated lower CV and greater ICC across most metrics compared to non-athletes. Full article

Instrumented gait analysis is widely used in clinical settings for the early detection of neurological disorders, monitoring disease progression, and evaluating fall risk. However, the gold-standard marker-based 3D motion analysis is limited by high time and personnel demands. Advances in computer vision now enable markerless whole-body tracking with high accuracy. Here, we present vGait, a comprehensive 3D gait assessment method using a single RGB-D sensor and state-of-the-art pose-tracking algorithms. vGait was validated in healthy participants during frontal- and sagittal-perspective walking. Performance was comparable across perspectives, with vGait achieving high accuracy in detecting initial and final foot contacts (F1 scores > 95%) and reliably quantifying spatiotemporal gait parameters (e.g., stride time, stride length) and whole-body coordination metrics (e.g., arm swing and knee angle ROM) at different levels of granularity (mean, step-to-step variability, side asymmetry). The flexibility, accuracy, and minimal resource requirements of vGait make it a valuable tool for clinical and non-clinical applications, including outpatient clinics, medical practices, nursing homes, and community settings. By enabling efficient and scalable gait assessment, vGait has the potential to enhance diagnostic and therapeutic workflows and improve access to clinical mobility monitoring. Full article

Isokinetic metrics are suggested to be related to vertical jump performance, but little is known about the possible sex differences in this relationship in adolescent track and field athletes. The aim of the study was to examine the possible sex differences in the strength of the relationship between the kinetic parameters of the vertical squat jump with arms akimbo, the countermovement jump with arms akimbo, and the countermovement jump with free arm swing with the isokinetic parameters of the knee extensor and flexor muscles (angular velocities: 60°/s and 300°/s). In total, 35 (males: 21, females: 14) U18 track and field athletes were examined. The results revealed that the Men U18 group had higher vertical jump performance, higher values in the kinetic parameters of the vertical jump tests, higher knee extensor torque, and higher knee flexor torque in the non-dominant leg compared to the Women U18 group. Significant (p < 0.05) sex differences were observed in the relationship between the isokinetic parameters and the vertical jump performance metrics, as the Women U18 athletes relied more on the knee flexor torque than Men U18 athletes, and demonstrated a stronger negative relationship between selected isokinetic metrics and the pre-stretch gain in the vertical jump tests. In conclusion, it is recommended that young female track and field athletes minimize interlimb asymmetry and improve the convention ratio in their non-dominant leg to optimize vertical jump performance. Full article

The aim of the study was to examine the inter-limb asymmetry in force application in a 1-s maximum isometric leg press test (ISOM) and vertical jump tests without an arm swing (VJ)of male long jumpers. Nine experienced jumpers (age: 18–30 y, LJ personal best: 6.50–8.05 m) were examined. Participants performed: (a) bilateral VJs from the squatting position (SQJ) and with a countermovement (CMJ), (b) unilateral CMJ from the take-off (TOL) and swing (SWL) leg used in the LJ take-off, and c) bilateral 1-s ISOM tests. Data were collected for each lower limb with separate force dynamometers (sampling frequency: VJs = 1 kHz, ISOM = 500 Hz). The inter-limb asymmetry of the peak applied force was evaluated using the symmetry angle. The paired samples T-test revealed non-significant (p > 0.05) inter-limb differences for the force output in the bilateral jump tests, in the unilateral jump tests, and in the ISOM. In conclusion, despite the fact that a powerful unilateral take-off is required for the optimization of long jump performance, no asymmetry was found in the examined tests, suggesting that the dominant/take-off leg was not stronger than the contra-lateral leg. This is possibly due to the intensive execution of other bilateral tasks involved, like the approach run. Full article

We tested the feasibility of one session of treadmill training using a novel physical therapist assisted system (Mobility Rehab) using wearable sensors on the upper and lower limbs of 10 people with Parkinson’s disease (PD). Participants performed a 2-min walk overground before and after 15 min of treadmill training with Mobility Rehab, which included an electronic tablet (to visualize gait metrics) and five Opal sensors placed on both the wrists and feet and on the sternum area to measure gait and provide feedback on six gait metrics (foot-strike angle, trunk coronal range-of-motion (ROM), arm swing ROM, double-support duration, gait-cycle duration, and step asymmetry). The physical therapist used Mobility Rehab to select one or two gait metrics (from the six) to focus on during the treadmill training. Foot-strike angle (effect size (ES) = 0.56, 95% Confidence Interval (CI) = 0.14 to 0.97), trunk coronal RoM (ES = 1.39, 95% CI = 0.73 to 2.06), and arm swing RoM (ES = 1.64, 95% CI = 0.71 to 2.58) during overground walking showed significant and moderate-to-large ES following treadmill training with Mobility Rehab. Participants perceived moderate (60%) and excellent (30%) effects of Mobility Rehab on their gait. No adverse events were reported. One session of treadmill training with Mobility Rehab is feasible for people with mild-to-moderate PD. Full article

The purpose of the study was to examine the effect of spinal asymmetries on specific physical fitness parameters in young elite soccer players. Fifty male soccer players, all members of the under 17 (U17) and 15 (U15) National teams of Cyprus, were initially evaluated for thoracic kyphosis, lumbar lordosis and scoliosis asymmetries. Based on the spinal asymmetries’ initial evaluation, soccer players were categorized into the asymmetry group (AG) and normal group (NG) per spinal asymmetry. Hamstring and lower-back flexibility, countermovement jump (CMJ) and lower body isokinetic maximum force were evaluated between AG and NG. CMJ with arm swing was lower in kyphotic posture AG compared with the NG (AG: 41.70 ± 3.59 cm, NG: 44.40 ± 4.34 cm; p = 0.028). Single leg CMJ was lower in both legs in scoliotic posture AG compared with the NG (right: AG: 17.42 ± 1.86 cm, NG: 19.16 ± 2.42 cm, p = 0.008, left: AG: 17.54 ± 1.33 cm, NG: 19.97 ± 2.91 cm; p = 0.002). Sit-and-reach flexibility was lower in scoliotic posture AG (AG: 20.44 ± 5.76 cm, NG: 24.82 ± 6.83 cm; p = 0.024) and higher in lordotic posture AG (AG: 25.95 ± 6.59 cm, NG: 21.73 ± 6.45 cm; p = 0.04) both compared with the NG. No significant difference was found for quadriceps and hamstrings concentric peak torque between the AG and NG (p > 0.05). The current study revealed that kyphotic and scoliotic posture asymmetries deteriorate neuromuscular explosiveness performance and diminish lower limbs’ flexibility in young International-level soccer players. Full article

Motor impairments are among the most relevant, evident, and disabling symptoms of Parkinson’s disease that adversely affect quality of life, resulting in limited autonomy, independence, and safety. Recent studies have demonstrated the benefits of physiotherapy and rehabilitation programs specifically targeted to the needs of Parkinsonian patients in supporting drug treatments and improving motor control and coordination. However, due to the expected increase in patients in the coming years, traditional rehabilitation pathways in healthcare facilities could become unsustainable. Consequently, new strategies are needed, in which technologies play a key role in enabling more frequent, comprehensive, and out-of-hospital follow-up. The paper proposes a vision-based solution using the new Azure Kinect DK sensor to implement an integrated approach for remote assessment, monitoring, and rehabilitation of Parkinsonian patients, exploiting non-invasive 3D tracking of body movements to objectively and automatically characterize both standard evaluative motor tasks and virtual exergames. An experimental test involving 20 parkinsonian subjects and 15 healthy controls was organized. Preliminary results show the system’s ability to quantify specific and statistically significant (p < 0.05) features of motor performance, easily monitor changes as the disease progresses over time, and at the same time permit the use of exergames in virtual reality both for training and as a support for motor condition assessment (for example, detecting an average reduction in arm swing asymmetry of about 14% after arm training). The main innovation relies precisely on the integration of evaluative and rehabilitative aspects, which could be used as a closed loop to design new protocols for remote management of patients tailored to their actual conditions. Full article

Arm swinging is a typical feature of human walking: Continuous and rhythmic movement of the upper limbs is important to ensure postural stability and walking efficiency. However, several factors can interfere with arm swings, making walking more risky and unstable: These include aging, neurological diseases, hemiplegia, and other comorbidities that affect motor control and coordination. Objective assessment of arm swings during walking could play a role in preventing adverse consequences, allowing appropriate treatments and rehabilitation protocols to be activated for recovery and improvement. This paper presents a system for gait analysis based on Microsoft Azure Kinect DK sensor and its body-tracking algorithm: It allows noninvasive full-body tracking, thus enabling simultaneous analysis of different aspects of walking, including arm swing characteristics. Sixteen subjects with Parkinson’s disease and 13 healthy controls were recruited with the aim of evaluating differences in arm swing features and correlating them with traditional gait parameters. Preliminary results show significant differences between the two groups and a strong correlation between the parameters. The study thus highlights the ability of the proposed system to quantify arm swing features, thus offering a simple tool to provide a more comprehensive gait assessment. Full article

Analyzing asymmetry from biomechanical parameters of the lower extremities has become a standard practice for accurate assessment of athletic performance, injury prevention, and rehabilitation. The aims of this study were (1) to determine differences between explosive strength and asymmetry of the lower extremities using kinetic parameters of the CMJ jump test in young female athletics, and (2) to investigate correlation between speed and asymmetry, as speed and kinetic parameters. The two groups of nine female sprinters (mean ± SD; G1-age 15.6 ± 1.34 years, height 170.1 ± 0.57 cm, body mass 62.54 ± 7.73 kg, and BMI 21.6 ± 2.05; G2-age 16.2 ± 1.3 years, height 168.4 ± 0.61 cm, body mass 57.69 ± 3.12 kg, and BMI 20.37 ± 1.38) performed the CMJ test without using an arm swing, as well as a 100 m test. Two tensiometric platforms were used for the kinetic parameters and asymmetry. Asymmetry was calculated by an AI equation, and the values of the takeoff velocities and jump height parameters were obtained by integral formula and the trapezoidal rule of impulse-momentum methods. The results show differences in four kinetic parameters: height (G1- 26.82 ± 3.56 cm, vs. G2- 17.45 ± 2.01 cm), concentric impulse, (G1- 96.05 ± 16.95 N⋅s, vs. G2- 68.41 ± 4.77 N⋅s), takeoff velocity, (G1- 2.29 ± 0.14 m/s, vs. 1.83 ± 0.12 m/s), and concentric velocity, m/s (G1- 1.5 ± 0.175 m/s, vs. 1.17 ± 0.122 m/s), as well as a negative strong and very strong correlation between asymmetry and kinetic parameters for three parameters: Peak Force (G1- r = −0.878, and all subjects r = −0.633), Eccentric Impulse of left leg (G1- r = −0.865) and Concentric Impulse of right leg (G2- r = −0.878), (p <.05). The younger sprinters did not show the principle of muscle activation in the form of a longer preparatory phase of contact time, eccentric and concentric phase, as well as a force impulse that is optimal. There was no correlation between asymmetry and sprint performance. Full article

Assessment of the inter-limb asymmetry of leg stiffness is carried out using one-legged jumping tasks. However, the level of asymmetry may vary depending on the performance on one or both lower limbs. Therefore, the purpose of this study was to identify the differences in leg stiffness between the dominant and non-dominant lower limb during a two-legged countermovement jump. The research was conducted on 35 s-league basketball players (body height: 1.90 ± 0.08 m, body mass: 81.9 ± 10 kg, age: 19.5 ± 1.7 years). Each participant performed three countermovement jumps with arm swing to the maximum height. Measurements employed a BTS SMART motion analysis system and two Kistler force plates. Statistically significant differences were found during the comparison of leg stiffness in the dominant and non-dominant lower limbs. Inter-limb asymmetry of leg stiffness reached 22.0% in the countermovement phase and 8.9% in the take-off phase. Significant inter-limb asymmetry of leg stiffness might lead to injury or considerably reduce the performance of athletes. Therefore, an important role is to conduct strength and speed-strength trainings with proper loads to both body sides. Coaches should pay more attention to similar lower limbs movement patterns during two-legged exercises and bilateral strength development. Full article

Arm swing during gait has been positively related to gait stability and gait efficiency, particularly in the presence of neurological disorders that affect locomotion. However, most gait studies have focused on lower extremities, while arm swing usually remains ignored. In addition, these studies are mostly based on costly, highly-specialized vision systems or on wearable devices which, despite their popularity among researchers and specialists, are still relatively uncommon for the general population. This work proposes a way of estimating arm swing asymmetry from a single 2D gait video. First, two silhouette-based representations that separately capture motion data from both arms were built. Second, a measure to quantify arm swing energy from such a representation was introduced, producing two side-dependent motion measurements. Third, an arm swing asymmetry index was obtained. The method was validated on two public datasets, one with 68 healthy subjects walking normally and one with 10 healthy subjects simulating different styles of arm swing asymmetry. The validity of the asymmetry index at capturing different arm swing patterns was assessed by two non-parametric tests: the Mann–Whitney U test and the Wilcoxon signed-rank test. The so-called physiological asymmetry was observed on the normal gait sequences of both datasets in a statistically similar way. The asymmetry index was able to fairly characterize the different levels of asymmetry simulated in the second set. Results show that it is possible to estimate the arm swing asymmetry from a single 2D gait video, with enough sensitivity to discriminate anomalous patterns from normality. This opens the door to low-cost easy-to-use mobile applications to assist clinicians in monitoring gait condition in primary care (e.g., in the elderly), when more accurate and specialized technologies are often not available. Full article

In patients with Parkinson’s disease (PD), arm swing changes are common, even in the early stages, and these changes are usually evaluated subjectively by an expert. In this article, hypothesize that arm swing changes can be detected using a low-cost, cloud-based, wearable, sensor system that incorporates triaxial accelerometers. The aim of this work is to develop a low-cost, assistive diagnostic tool for use in quantifying the arm swing kinematics of patients with PD. Ten patients with PD and 11 age-matched, healthy subjects are included in the study. Four feature extraction techniques were applied: (i) Asymmetry estimation based on root mean square (RMS) differences between arm movements; (ii) posterior–anterior phase and cycle regularity through autocorrelation; (iii) tremor energy, established using Fourier transform analysis; and (iv) signal complexity through the fractal dimension by wavelet analysis. The PD group showed significant (p < 0.05) reductions in arm swing RMS values, higher arm swing asymmetry, higher anterior–posterior phase regularities, greater “high energy frequency” signals, and higher complexity in their XZ plane signals. Therefore, the novel, portable system provides a reliable means to support clinical practice in PD assessment. Full article

Vertical jump is a relevant variable in the classification of football for individuals with cerebral palsy. In this regard, the literature is limited. There are no studies assessing vertical jumping ability through kinematic methods and in more specific football game situations, such as jumps with a header. The goals of the present study were to assess how the modification of jumping conditions (without and with a header) might affect the kinematic and kinetic parameters of counter movement jumping, and whether the functional profiles of the players constrain their ability to jump vertically, both with and without a header. Thirteen male football players with cerebral palsy (27.7 ± 5.7 years old) and different functional profiles participated in this study. All the players performed ten counter movement jumps with arms swing, five headed a ball and five did not. The kinematic parameters were recorded with a 3D motion analysis system, and the kinetic parameters using a force platform. Significantly smaller angles of the hips (d_g = 0.75–0.79; p < 0.01) and knees (d_g = 1.04–1.15; p < 0.05), as well as greater ankle extension (d_g = −0.71; p < 0.05), were observed during the eccentric phase of the jumps with a header. There were also asymmetries between legs in ankle extension during jumps with a header (d_g = −1.06; p < 0.05), which could be an adjustment element for the precision of the jumps (i.e., header action). It should be mentioned that the jumping pattern could be partially affected by the functional profile of football players with cerebral palsy. Full article

The purpose of the present study was to establish the intrasession and intersession reliability of variables obtained from a force plate that was used to quantitate lower extremity inter-limb asymmetry during the bilateral countermovement jump (CMJ). Secondarily, a comparison was performed to determine the influence of the jump protocol CMJ with or without an arm swing (CMJ AS and CMJ NAS, respectively) on inter-limb asymmetries. Twenty-two collegiate basketball players performed three CMJ AS and three CMJ NAS on dual force platforms during two separate testing sessions. A majority of variables met the acceptable criterion of intersession and intrasession relative reliability (ICC > 0.700), while fewer than half met standards established for absolute reliability (CV < 10%). CMJ protocol appeared to influence asymmetries; Concentric Impulse-100 ms, Eccentric Braking Rate of Force Development, Eccentric Deceleration, and Force at Zero velocity were significantly different between jumping conditions (CMJAS versus CMJ NAS; p < 0.05). The present data establish the reliability and smallest worthwhile change of inter-limb asymmetries during the CMJ, while also identifying the influence of CMJ protocol on inter-limb asymmetries, which can be useful to practitioners and clinicians in order to effectively monitor changes associated with performance, injury risk, and return-to-play strategies. Full article