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The COVID-19 pandemic has transformed daily life, as individuals engage in social distancing to prevent the spread of the disease. Consequently, patients' access to outpatient rehabilitation care was curtailed and their prospect for recovery has been compromised. Telerehabilitation has the potential to provide these patients with equally-efficacious therapy in their homes. Using commercial gaming devices with embedded motion sensors, data on movement can be collected toward objective assessment of motor performance, followed by training and documentation of progress. Herein, we present a low-cost telerehabilitation system dedicated to bimanual exercise, wherein the healthy arm drives movements of the affected arm. In the proposed setting, a patient manipulates a dowel embedded with a sensor in front of a Microsoft Kinect sensor. In order to provide an engaging environment for the exercise, the dowel is interfaced with a personal computer, to serve as a controller. The patient's gestures are translated into interactive actions in a custom-made citizen-science project. Along with the system, we introduce an algorithm for classification of the bimanual movements, whose inner workings are detailed in terms of the procedures performed for dimensionality reduction, feature extraction, and movement classification. We demonstrate the feasibility of our system on eight healthy subjects, offering support to the validity of the algorithm. These preliminary findings set forth the development of precise motion analysis algorithms in affordable home-based rehabilitation.

BackgroundCam and/or pincer morphologies (CPM) are potential precursors to hip osteoarthritis (OA) and important contributors to non-arthritic hip pain. However, only some CPM hips develop OA and/or pain, and it is not clear why. Anterior impingement between the femoral head/neck contour and acetabular rim during motion is a proposed pathomechanism. Understanding how activity and deformity combine to produce impingement may shed light on the causes of hip degeneration/pain. The objective of this study was to determine the accuracy of a subject-specific hip model driven by subject-specific motion data in predicting anterior impingement.MethodsWe recruited 22 participants with CPM (both with and without pain) and 11 controls. We collected subject-specific 3D kinematics during squatting and sitting flexion, adduction, and internal rotation (FADIR) (an active and a passive maneuver, respectively, proposed to provoke impingement). We then developed 3D subject-specific hip models from supine 3T hip MRI scans that predicted the beta angle (a measure of anterior femoroacetabular clearance) for each frame of acquired kinematics. To assess the accuracy of these predictions, we measured the beta angle directly in the final position of squatting and sitting FADIR using open MRI scans. We selected the frame of motion data matching the static imaged posture using the least-squares error in hip angles. Model accuracy for each subject was calculated as the absolute error between the open MRI measure of beta and the model prediction of beta at the matched time frame. To make the final model accuracy independent of goodness of match between open MRI position and motion data, a threshold was set for least-squares error in hip angles, and only participants that were below this threshold were considered in the final model accuracy calculation, yielding results from 10 participants for squatting and 7 participants for sitting FADIR.ResultsFor squatting and sitting FADIR, we found an accuracy of 1.1°(0.8°) and 1.3°(mean (SD), and root mean squared error, respectively) and 0.5°(0.3°) and 0.6°, respectively.ConclusionThis subject-specific hip model predicts anterior femoroacetabular clearance with an accuracy of about 1°, making it useful to predict anterior impingement during activities measured with motion analysis.

This study's purpose was to compare the kinematic demands placed on the knee and the hip during various biomechanical tests.Retrospective cross-sectional design.A university research laboratory.The study sample consisted of 70 NCAA Division I female athletes.During the performance of three test maneuvers, a drop vertical jump (DVJ), single leg cross over hop (COH) and modified T-test (AT), the hip and knee joint angles at maximum knee valgus were obtained from marker displacement data collected using a 20-camera motion analysis system. A linear mixed model was used to compare the effect of test on joint angle.A significant difference (p 0.001) in the frontal and sagittal plane position of the knee and hip was noted between the DVJ, COH, and AT tests at maximum knee valgus.The DVJ, COH, and AT maneuvers do not appear to place the same kinematic stress on the knee, supporting the need for the development of return to sport tests that mimic on field demands.

The basic technique of kicking in pencak silat was often overlooked due to the consideration of increasing the level of the athlete and not on competence or skill. The purpose of this study was to identify biomechanics analysis of pencak silat side kick of Persinas ASAD. This study used quantitative research to obtain data derived from video recordings of sidekick movements that were analyzed using the Dartfish version 8. The total participants in this test were 30 Persinas ASAD martial arts athletes. This study recorded 30 martial arts athletes from Persinas ASAD with an average age (15.37 ± 1.45 years old), height (160 ± 7.9 cm), weight (50.37 ± 8.61 kg), and leg length (86.37 ± 5.73 cm). The results of side kick motion analysis data are obtained from the video analysis using Dartfish version 8 where the focus of the movement is divided into 3 main phases. These phases include the horse stance, the take-off phase, and the impact phase. The results found that the fighters are in the appropriate category. To get very appropriate category, the participants were expected to improve the ability of the components of speed, accuracy, and reaction speed to be more effective and efficient. Further research was expected to do a motion analysis using video recordings high speed camera on the frontal and sagittal angles.

While gait termination is challenging for children with spastic cerebral palsy (CCP), few studies have quantitatively assessed this issue.What are the characteristics of center of mass (COM) and center of pressure (COP) displacement during gait termination in CCP, and how do they compare with those in children with typical development (CTD)?This cross-sectional study included 13 adults with typical development (19.85 ± 0.52 years), 12 CTD (10.41 ± 2.98 years), and 16 CCP (11.15 ± 2.71 years). Participants were instructed to immediately stop walking when a stop sign appeared on a screen, which was placed at the end of an 8-m walkway. COM and COP were determined via 3-dimensional motion analysis and force plate data. Differences between the groups were assessed using the two sample t-test or Wilcoxon rank sum test. The level of statistical significance was set at P0.05.The normalized time for stopping in CCP (4.556 ± 0.602) was higher than that in CTD (3.617 ± 0.545, P0.001). The normalized COP displacement (P0.001) and divergence between COM and COP (P0.001) in the mediolateral (ML) direction were significantly higher in CCP than CTD. However, the normalized divergence between COM and COP in the anteroposterior (AP) direction in CCP was lower than that in CTD (P = 0.034).The more minor divergence between COM and COP in the AP direction and the more significant COP displacement in the ML direction cause difficulty to exert braking force during gait termination. Thus, CCP require a longer time for gait termination. This finding may facilitate the development of interventions for improving gait in CCP.

Rotational deformities following intramedullary (IM) nailing of tibia has a reported incidence of as high as 20%. Common techniques to measure deformities following IM nailing of tibia are either based on clinical assessment, plain X-rays or Computed Tomography (CT) comparing the treated leg with the uninjured contralateral side. All these techniques are based on examiners manual calculation inherently subject to bias. Following our previous rigorous motion analysis and symmetry studies on hemi pelvises, femurs and orthopaedic implants, we aimed to introduce a novel fully digital technique to measure rotational deformities in the lower legs. Following formal institutional approval from the Imperial College, CT images of 10 pairs of human lower legs were retrieved. Images were anonymized and uploaded to a research server. Three dimensional CT images of the lower legs were bilaterally reconstructed. CT-based motion analysis (CTMA) was used and the mirrored images of the left side were merged with the right side proximally as stationary and distally as moving objects. Discrepancies in translation and rotation were automatically calculated. Our study population had a mean age of 54 ± 20 years. There were six males and four females. We observed a greater variation in translation (mm) of Centre of Mass (COM) in sagittal plane (95% CI − 2.959–.292) which was also presented as rotational difference alongside the antero-posterior direction or Y axis (95% CI .370–1.035). In other word the right lower legs in our study were more likely to be in varus compared to the left side. However, there were no statistically significant differences in coronal or axial planes. Using our proposed fully digital technique we found that lower legs of the human adults were symmetrical in axial and coronal plane. We found sagittal plane differences which need further addressing in future using bigger sample size. Our novel recommended technique is fully digital and commercially available. This new technique can be useful in clinical practice addressing rotational deformities following orthopaedic surgical intervention. This new technique can substitute the previously introduced techniques.

Background/objective: There is a lack of information about relationship between physical characteristics and biomechanics of the lower extremity during the squat. Additionally, studies did not examine sex-related differences. The purpose of this study was to investigate relationships between physical characteristics and biomechanics of the lower extremity during the squat, and to determine if any sex differences are present. Methods: Fifty three participants recruited (21.82 ± 2.3 years; 75.56 ± 14.98 kg; 171.57 ± 8.38 cm) performed three squats with 75% of one repetition maximum. Femur to tibia length ratio, hip and ankle joints’ flexibilities, and relative muscular strength were measured and used as physical characteristics. Net joint torques (NJT) and flexion angles of the lower extremity were extracted as dependent variables. Multiple regression (stepwise) analysis was conducted to examine the relationships with physical characteristics being factors. Pearson correlation coefficients were calculated to determine intercorrelations among the dependent variables. Results: Relative muscular strength was related to hip NJT and knee flexion angle, and hip flexibility was related to ankle dorsiflexion. Hip and knee NJT showed moderate correlations with the corresponding flexion angles (r = 0.48-0.53; p

BACKGROUND An ankle-foot orthosis with an oil damper (AFO-OD) may improve kinetics and kinematics for efficient walking after stroke. Yet it is unknown whether hemiplegic walking behaves like "inverted-pendulum" gait and how it is modulated by using AFO-ODs for efficiency. OBJECTIVES This study examined whether the use of AFO-ODs improves the kinetics of total vertical ground reaction force (vGRF) and kinematics of vertical pelvic displacement (vPD) in different walking phases, and gait speed following stroke. Also, the relationship between those gait parameters was examined to assess efficient walking. STUDY DESIGN Observational study within subject. METHODS Eight participants with hemiplegia walked at self-selected speed without and with AFO-ODs over the walkway and gait speed was measured. Force plates were used to measure total vGRF during the double-limb support phase with the paretic leading limb and with the paretic trailing limb (DSPT). The vPD in the paretic and nonparetic stance phases was measured by a three-dimensional motion analysis system. RESULTS Without AFO-ODs, reduced total vGRF during DSPT was related to greater vPD in the subsequent nonparetic stance. Using AFO-ODs significantly increased gait speed and total vGRF during double-limb support phase with the paretic leading limb and during DSPT, which were significantly correlated. Vertical pelvic displacement in the nonparetic stance was higher than the paretic stance in both conditions. CONCLUSIONS Decreased total vGRF during DSPT was compensated by excessive vPD in the nonparetic stance phase without AFO-ODs, indicating inefficient walking. However, the use of AFO-ODs improved the kinetic energy of total vGRF during the double-limb support phase, contributing to efficient walking. CLINICAL RELEVANCE STATEMENT The AFO-ODs can be used to improve kinetic energy and to modulate functions in the weight transition during the double-limb support phase, with faster walking speed. Thus, AFO-ODs can be considered to be therapeutic AFOs to acquire efficient walking performance in poststroke rehabilitation.

International audience; Introduction: This study explores the value of using motion analysis to evaluate cervical and jaw ROM on students with or without bruxism when comparing Osteopathic Manipulative Treatment (OMT) to sham in school settings. Methods: A feasibility study was run with 48 volunteer students from an osteopathic educational institution. Random sequence for allocation was generated using a 1:1 ratio and block size of four to either OMT or sham treatment (control group). The chosen motion outcomes of interest were the lateral jaw range of motion, jaw opening, cervical rotation and side-bending. ROM was measured averaging over three repeated movements at baseline, immediately after the 1st treatment, one week before the 2nd treatment, and immediately after the second treatment using video-based analysis with 15 body landmarks. Results: Repeated measures of joint motion at baseline showed high levels of reliability (ICC ranging from 0.953 to 0.985). Motion analysis detected clinically important differences between OMT and sham one-week posttreatment for jaw lateral ROM (3.3 degrees; p = 0.018) and cervical rotation ROM (12.0 degrees; p = 0.003) in participants with bruxism but not in those without. Magnitude of differences were increased for all parameters following the second treatment (lateral jaw movement; 4.8 degrees, p = 0.005; jaw opening; 5.5 degrees, p = 0.002; cervical side-bending; 9.2 degrees, p = 0.023; cervical rotation; 18.2 degrees, p < 0.001). Conclusion: Motion analysis is capable of detecting the effects of OMT on cervical and jaw ROM in students with bruxism but not without. Finally, the study showed the feasibility of introducing usual standards for clinical trials and sham treatment in an educational setting with students.

Background The conventional gait model (CGM) is commonly utilised within clinical motion analysis but has a number of inherent limitations. To overcome some of these limitations modifications have been made to the CGM and six-degrees of freedom models (6DoF) have been developed. Research Question How comparable are lower limb kinematics calculated using modified CGM and 6DoF models and what is the error associated with the output of each model during walking? Methods Ten healthy males attended two gait analysis sessions, in which they walked at a self-selected pace, while a 10-camera motion capture system recorded lower limb kinematics. Hip, knee and ankle joint kinematics in all three anatomical planes were calculated using a modified CGM, with medial anatomical markers and a three-dimensional foot added, and 6DoF. Mean absolute differences were calculated on a point-by-point basis over the walking gait cycle and interpreted relative to a 5° threshold to explore the comparability of model outputs. The standard error of the measurement (SEM) was also calculated on a point-by-point basis over the walking gait cycle for each model. Results Mean absolute differences above 5° were reported between the two model outputs in 58–86% of the walking gait cycle at the knee in the frontal plane, and over the entire walking gait cycle at the hip and knee in the transverse plane. SEM was typically larger for the modified CGM compared to the 6DoF, with the highest SEM values reported at the knee in the frontal plane, and the hip and the knee in the transverse plane. Significance Caution should be taken when looking to compare findings between studies utilising modified CGM and 6DoF outside of the sagittal plane, especially at the hip and knee. The reduced SEM associated with the 6DoF suggests this modelling approach may be preferable.

In patients with dropped head syndrome (DHS), cervical malalignment is one of the risk factors for impaired horizontal gaze and restrictions to ambulation. The characteristics of gait in patients with DHS have not been clarified biomechanically from the viewpoint of dynamic alignment and lower limb kinematics. This study aimed to clarify kinematic and kinetic differences during level walking in patients with DHS compared to the healthy elderly. Twelve patients with DHS and healthy elderly individuals performed level walking at a self-selected speed. Spatiotemporal, kinematic, and kinetic data were recorded using a three-dimensional motion analysis system. Statistical analysis was performed to compare these data between the two groups, respectively. Compared with the healthy elderly, stride length and peak hip-joint extension angle in patients with DHS were significantly shorter and smaller. The thorax was also significantly tilted backwards. Peak ankle-joint plantar-flexion moment was significantly smaller despite larger dorsiflexion angle compared with the healthy elderly. The walking of DHS patients demonstrated kinematic and kinetic characteristics of the lower limb joints and alignment of the thorax and pelvis corresponding to their short stride and walking speed.

The purpose of this study was to assess the change of dynamic alignment after the short and intensive rehabilitation (SHAiR) program in patients with dropped head syndrome (DHS). Eighteen patients with DHS patients who complained of their inability to maintain horizontal gaze and underwent the SHAiR program. Patients performed level walking at a self-selected speed. Spatiotemporal, kinematic, and kinetic data were recorded using a three-dimensional motion analysis system. Statistical analysis was performed to compare these data before and after the SHAiR program. Those who underwent the SHAiR program showed a significant increase in the head angle and stride length compared to pre-treatment measurements (p 0.05). The SHAiR program modifies the malalignment of the head and neck and spatiotemporal parameters in DHS patients during level walking.

Background Our aim was to characterize the motions of multiple laparoscopic surgical instruments among participants with different levels of surgical experience in a series of wet-lab training drills, in which participants need to perform a range of surgical procedures including grasping tissue, tissue traction and dissection, applying a Hem-o-lok clip, and suturing/knotting, and digitize the level of surgical competency. Methods Participants performed tissue dissection around the aorta, dividing encountered vessels after applying a Hem-o-lok (Task 1), and renal parenchymal closure (Task 2: suturing, Task 3: suturing and knot-tying), using swine cadaveric organs placed in a box trainer under a motion capture (Mocap) system. Motion-related metrics were compared according to participants’ level of surgical experience (experts: 50 ≤ laparoscopic surgeries, intermediates: 10–49, novices: 0–9), using the Kruskal–Wallis test, and significant metrics were subjected to principal component analysis (PCA). Results A total of 15 experts, 12 intermediates, and 18 novices participated in the training. In Task 1, a shorter path length and faster velocity/acceleration/jerk were observed using both scissors and a Hem-o-lok applier in the experts, and Hem-o-lok-related metrics markedly contributed to the 1st principal component on PCA analysis, followed by scissors-related metrics. Higher-level skills including a shorter path length and faster velocity were observed in both hands of the experts also in tasks 2 and 3. Sub-analysis showed that, in experts with 100 ≤ cases, scissors moved more frequently in the “close zone (0 ≤ to Conclusion Our novel Mocap system recognized significant differences in several metrics in multiple instruments according to the level of surgical experience. “Applying a Hem-o-lok clip on a pedicle” strongly reflected the level of surgical experience, and zone-metrics may be a promising tool to assess surgical expertise. Our next challenge is to give completely objective feedback to trainees on-site in the wet-lab.

Traditional stepping in the zenkutsu-dachi stance of the Shotokan style of karate is very physically demanding. It requires considerably more effort than what is expended during conventional human bipedalism. We performed a biomechanical study to analyze and compare these two types of gaits when performed by a highly experienced karateka. The study involved a three-dimensional motion analysis system (digital cameras and optical reflectors) and a force platform to analyze the ground reaction forces in all three planes. The study had both kinematic and kinetic components. We found that zenkutsu-dachi stepping is much more costly from an energetics point of view because the properties of the biarticular muscles are not used, the muscular moments of force are higher, and the body's potential energy is not converted into kinetic energy, contrary to the more economical model of human bipedalism that involves an inverted pendulum pattern.

Background: The aim is to quantify and analyse tumour motion during a course of treatment for lung SBRT patients. Material and methods: Peak-to-peak motion of 483 tumours in 441 patients treated with peripheral lung SBRT at a single institution over a two year period was measured on planning CT and at all treatment fractions. Planning 4D-CT scans were analysed using our clinical workflow involving deformable propagation of the delineated target to all phases. Similarly, acquisition of the 4D-CBCT data followed the clinical workflow based on XVI 5.0 available on Elekta linacs. Differences and correlations of the peak-to-peak motion on the planning CT and at treatment were analysed. Results: On the planning CT, a total of 81.4% of the tumours had a peak-to-peak motion 7 mm) at the first fraction were evaluated individually, and they all had poor 4DCT image quality. The difference between the first and second/third fractions had a mean and standard deviation of 0.4 mm/0.5 mm and 2.0 mm/1.9 mm. Conclusion: Tumour motion at first treatment was similar to motion at planning, and motion at subsequent treatments was very similar to motion at first treatment. Large tumour motions are located towards the caudal posterior tumour locations. Patients with poor 4D-CT image quality should be closely followed at the first treatment to verify the motion.

BACKGROUND: Gait impairment is an essential symptom of Parkinson’s disease (PD). OBJECTIVE: This paper introduces a novel computer-vision framework for automatic classification of the severity of gait impairment using front-view motion analysis. METHODS: Four hundred and fifty-six videos were recorded from 19 PD patients using an RGB camera during clinical gait assessment. Gait performance in each video was rated by a neurologist using the unified Parkinson’s disease rating scale for gait examination (UPDRS-gait). The proposed algorithm detects and tracks the silhouette of the test subject in the video to generate a height signal. Gait features were extracted from the height signal. Feature analysis was performed using the Kruskal-Wallis rank test. A support vector machine was trained using the features to classify the severity levels according to UPDRS-gait in 10-fold cross-validation. RESULTS: Features significantly (p< 0.05) differentiated between median-ranks of UPDRS-gait levels. The SVM classified the levels with a promising area under the ROC of 80.88%. CONCLUSION: Findings support the feasibility of this model for Parkinson’s gait assessment in the home environment.

This review article summarized the literature regarding running gait. It describes characteristics of running gait and running gait cycle, explains running anatomy in relation to lower and upper body mechanism; contribution of muscles, and joint running gait cycle. The concept of running kinematics and kinetics has described motion characteristics such as position, velocity, acceleration, and force applied during the running cycle. Running gait analysis techniques has discussed such as motion analysis, force plate analysis, and electromyography.

Diagnosis and progress monitoring of frozen shoulder rely on correct measurement of active and passive range of motion (ROM) of shoulder. This paper studied the feasibility of a wearable inertial sensor network (WISN) and its associated shoulder ROM estimation algorithm for shoulder ROM assessment. The WISN composed of three inertial modules were placed on the trunk, upper arm, and forearm of human for assessment of shoulder ROM in real time. Each inertial module consists of an ARM-based 32-bit microcontroller, a triaxial accelerometer, a triaxial gyroscope, a triaxial magnetometer, and a controller area network (CAN) transceiver. The measured accelerations, angular velocities, and magnetic signals generated by the human shoulder movements are transmitted to a personal computer via a Bluetooth wireless transmission module. The proposed shoulder ROM estimation algorithm includes the procedures of data collection, signal preprocessing, quaternion-based orientation estimation, and shoulder joint compensation. In order to evaluate shoulder ROM accurately, accelerations, angular velocities, and magnetic signals are integrated into a quaternion-based complementary nonlinear filter for minimizing the cumulative errors caused by the drift of the inertial sensors. Experimental results demonstrate that the WISN with the designed shoulder ROM estimation algorithm, compared to an optical motion analysis system (Vicon), have the average root mean square (RMS) angle errors ranging from 2.53° to 3.56°. In addition, the intra-tester reliability for each shoulder ROM measurement is excellent. The proposed WISN is a valid and reliable tool and can be used anywhere without any external reference device for convenient evaluation of shoulder ROM.

BACKGROUND CONTEXT: Radiographic evaluation in adult spinal deformity (ASD) offers no information on spinopelvic alignment and compensation during dynamic conditions. Motion analysis offers the potential to bridge the gap between static radiographic and dynamic alignment measurement, increasing our understanding on how ASD impacts function. PURPOSE: This study aimed to explore the changes in sagittal alignment and compensation strategies in ASD between upright standing and walking, compared to control subjects and within different sagittal alignment groups. Ten patients were measured pre- and six months postoperatively to explore the impact of surgical alignment correction on gait. STUDY DESIGN: Prospective study. SAMPLE SIZE: Full protocol: 58 ASD and 20 controls; Spinal kinematic analysis: 43 ASD and 18 controls; Postoperative analysis: 10 ASD. OUTCOME MEASURES: Standing and walking sagittal spinopelvic (thoracic kyphosis (TK), lumbar lordosis (LL), sagittal vertical axis (SVA), pelvis), and lower limb kinematics, spinopelvic changes between standing and walking (∆ ie, difference between mean dynamic and static angle), lower limb kinetics, spatiotemporal parameters, balance (BESTest), patient-reported outcome scores (SRS-22r, ODI, and FES-I) and radiographic parameters. METHODS: Motion analysis was used to assess the standing and walking spinopelvic and lower limb kinematics, as well as the lower limb kinetics during walking. All parameters were compared between controls and patients with ASD, divided in three groups based on their sagittal alignment (ASD 1: decompensated sagittal malalignment; ASD 2: compensated sagittal malalignment; ASD 3: scoliosis and normal sagittal alignment). Ten patients were reassessed 6 months after spinal corrective surgery. Continuous kinematic and kinetic data were analyzed through statistical parametric mapping. RESULTS: All patient groups walked with increased forward trunk tilt (∆SVA=41.43 mm, p

BACKGROUND: Motion analysis is commonly used to evaluate joint kinetics in children with cerebral palsy who exhibit gait disorders. However, one cannot readily infer muscle-tendon forces from joint kinetics. This study investigates the use of shear wave tensiometry to characterize Achilles and patellar tendon forces during gait. RESEARCH QUESTION: How do Achilles and patellar tendon wave speed and loading modulate with walking speed in typically developing children? METHODS: Twelve typically developing children (9 to 16 years old, walked on an instrumented treadmill with shear wave tensiometers over their Achilles (n=11) and patellar (n=9) tendons. Wave speeds were recorded at five leg length-normalized walking speeds (very slow to very fast). Achilles and patella tendon moment arms were measured with synchronized ultrasound and motion capture. The tendon wave speed-load relationship was calibrated at the typical walking speed and used to estimate tendon loading at other walking speeds. RESULTS: Characteristic Achilles and patellar tendon wave speed trajectories exhibited two peaks over a gait cycle. Peak Achilles tendon force closely aligned with peak ankle plantarflexor moment during pushoff, though force exhibited less modulation with walking speed. A second peak in late swing Achilles loading, which was not evident from the ankle moment, increased significantly with walking speed (p < 0.001). The two peaks in patellar tendon loading occurred at 13 ± 1% and 68 ± 6% of the gait cycle, matching the timing of peak knee extension moment in early stance and early swing. Both peak patellar tendon loads increased significantly with walking speed (p < 0.05). SIGNIFICANCE: This is the first study to use shear wave tensiometry to characterize Achilles and patellar tendon loading during gait in children. These data could serve as a normative comparison when using tensiometry to identify abnormal tendon loading patterns in individuals who exhibit equinus and/or crouch gait.

The objective of this study was to test the feasibility of using a pair of wearable inertial measurement unit (IMU) sensors to accurately capture dynamic joint motion data during simulated occupational conditions. Eleven subjects (5 males and 6 females) performed repetitive neck, low-back, and shoulder motions simulating low- and high-difficulty occupational tasks in a laboratory setting. Kinematics for each of the 3 joints were measured via IMU sensors in addition to a “gold standard” passive marker optical motion capture system. The IMU accuracy was benchmarked relative to the optical motion capture system, and IMU sensitivity to low- and high-difficulty tasks was evaluated. The accuracy of the IMU sensors was found to be very good on average, but significant positional drift was observed in some trials. In addition, IMU measurements were shown to be sensitive to differences in task difficulty in all 3 joints (P

This study quantified recovery of thumb motion in patients with carpal tunnel syndrome after carpal tunnel release using three-dimensional motion analysis with a retroreflective surface-based marker method. Eighteen hands from 14 patients who underwent carpal tunnel release for idiopathic carpal tunnel syndrome were included. The angular movements of the three joints of the thumb, the path length of the thumb tip and the area enclosed by the perimeter path of the thumb tip were measured during circumduction. The range of joint movement, including abduction/adduction of the trapeziometacarpal joint, and flexion/extension of the interphalangeal and metacarpophalangeal joints and the path length of the thumb tips, improved significantly 1 year after surgery. The quantification of thumb kinematics helps to better understand motor dysfunction in carpal tunnel syndrome, assess the severity of the condition and decide on treatment. Level of evidence: IV

Background/Objective Technical skill acquisition is an essential component of neurosurgical training. Educational theory suggests that optimal learning and improvement in performance depends on the provision of objective feedback. Therefore, the aim of this study was to develop a vision-based framework based on a novel representation of surgical tool motion and interactions capable of automated and objective assessment of microsurgical skill. Methods Videos were obtained from 1 expert, 6 intermediate, and 12 novice surgeons performing arachnoid dissection in a validated clinical model using a standard operating microscope. A mask region convolutional neural network framework was used to segment the tools present within the operative field in a recorded video frame. Tool motion analysis was achieved using novel triangulation metrics. Performance of the framework in classifying skill levels was evaluated using the area under the curve and accuracy. Objective measures of classifying the surgeons' skill level were also compared using the Mann–Whitney U test, and a value of P Results The area under the curve was 0.977 and the accuracy was 84.21%. A number of differences were found, which included experts having a lower median dissector velocity (P = 0.0004; 190.38 ms–1 vs. 116.38 ms–1), and a smaller inter-tool tip distance (median 46.78 vs. 75.92; P = 0.0002) compared with novices. Conclusions Automated and objective analysis of microsurgery is feasible using a mask region convolutional neural network, and a novel tool motion and interaction representation. This may support technical skills training and assessment in neurosurgery.

Objective Dynamic image analysis of carotid plaques has demonstrated that during systole and early diastole, all plaque components will move in the same direction (concordant motion) in some plaques. However, in others, different parts of the plaque will move in different directions (discordant motion). The aim of our study was (1) to determine the prevalence of discordant motion in symptomatic and asymptomatic plaques, (2) to develop a measurement of the severity of discordant motion, and (3) to determine the correlation between the severity of discordant motion and symptom prevalence. Methods A total of 200 patients with 204 plaques resulting in 50% to 99% stenosis (112 asymptomatic and 92 symptomatic plaques) had video recordings available of the plaque motion during 10 cardiac cycles. Video tracking was performed using Farneback's method, which relies on frame comparisons. In our study, these were performed at 0.1-second intervals. The maximum angular spread (MAS) of the motion vectors at 10-pixel intervals in the plaque area was measured in degrees. Plaques were classified as concordant (MAS, 120°). Results Motion was discordant in 89.1% of the symptomatic plaques but only in 17.9% of asymptomatic plaques (P < .001). The prevalence of symptoms increased with increasing MAS. For a MAS >120°, the hazard ratio for the presence of symptoms was 47.7 (95% confidence interval, 18.1-125.6) compared with the rest of the plaques after adjustment for the degree of stenosis and mean pixel motion. The area under the receiver operating characteristic curve for the prediction of the presence of symptoms using the MAS was 0.876 (95% confidence interval, 0.823-0.929). The use of the median MAS (120°) as a cutoff point classified 86% of the plaques correctly (sensitivity, 81.4%; specificity, 91.2%; positive predictive value, 90.2%; and negative predictive value, 83.0%). Conclusions The use of the MAS value to identify asymptomatic plaques at increased risk of developing symptoms and, in particular, stroke should be tested in prospective studies.

Multi-segment foot analysis is traditionally challenging to perform while subjects are wearing footwear or a foot orthosis and is difficult to apply in the clinical setting. A recently developed stretch strain sensor (STR), that is thin and highly flexible, may solve this limitation because it does not require observation using a camera and is highly portable.This study aimed to examine the reproducibility and validity of foot motion analysis using the STR during walking and running by comparing it with a conventional motion capture system.Twenty-one healthy participants were examined in this study. The STR was placed on the participant's foot in one of two locations in separate experiments (spring ligament; SL and navicular drop; ND methods). Foot kinematic data during walking and running were simultaneously recorded using the STR and a three-dimensional motion capture system. Intra-class correlation (ICC) was used to assess test-retest reproducibility of the STR method. Cross-correlation coefficient evaluated the similarity of the pattern of the signals between the two systems. Pearson and Spearman correlation analysis was used to evaluate the relationships between the STR measurement and angular excursion of the forefoot or hindfoot.The ICCs of the SL method were 0.95 and 0.96, and those of the ND method were 0.93 and 0.71 during walking and running, respectively. In the SL method, the pattern of the signals between the STR and forefoot frontal motion was strongly correlated. The STR measurement was significantly correlated with forefoot eversion excursion (walking: r=-0.67, running: r=-0.64, p 0.01 each). In the ND method, the STR signal was not associated with forefoot and hindfoot kinematics.Our results showed that the STR has acceptable reproducibility and validity of foot motion analysis. This system may enable measurement of foot motion while subjects are wearing shoes and outside the laboratory.

Background Rocker sole (RS) shoes have been linked to impaired postural control. However, which features of RS design affect balance is unclear. Research question Which RS design features affect standing balance and gait stability? Methods This study utilized an intervention and cross-over design. Twenty healthy young adults (10 males and 10 females) participated in this study. Standing balance and gait stability were measured using a single force platform and three-dimensional motion analysis system, respectively. The experimental conditions included the control shoe and five RS shoes in the combination of apex position (%) and apex angle (degree) for RS50-95, RS60-95, RS70-95, RS60-70, and RS60-110. The main outcome measures were the area surrounding the maximal rectangular amplitude, mean path length, average displacement of the center of pressure along the lateral and anterior/posterior directions, and maximal center of pressure excursion as the standing balance and lateral margin of stability as the gait stability. Statistical analyses were conducted using a two-way split-plot analysis of variance with repeated measures (with RS design as the within-subject factor and sex as the between-subject factor) and the Bonferroni post hoc test (α = .05). Results Regarding the mean path length, RS60-70 was significantly longer than the control shoe, and it showed a significantly increased lateral margin of stability. Thus, RS60-70 was shown to affect standing balance, limit of stability, and gait stability of the frontal plane during gait. Significance These results suggest that the apex angle of the RS design feature affects standing balance and gait stability, and RS60-70 is detrimental to stability. Therefore, when RS with a small apex angle is prescribed, it is necessary to consider the patient’s balance ability.

Background: Movement quality and neuromuscular balance are noted predictors of acute injury. Early sports specialization and extremely high activity levels have been linked to elevated risk of injury. Purpose: To investigate for any relationships among quality of physical movement, quantity of physical activity, and degree of sports specialization in a healthy cohort of active children and adolescents. Study Design: Cross-sectional study with prospectively collected data. Methods: Healthy children between the ages of 10 and 18 years were recruited and completed the Hospital for Special Surgery Pediatric Functional Activity Brief Scale to assess quantity of physical activity and the Jayanthi scale to assess degree of sports specialization (high, score of 2 or 3; low, score of 0 or 1). Movement quality was assessed using motion analysis sensors during 5 repetitions of 4 different jumping and squatting motions, with a maximum score of 100 per participant. Independent-samples t tests were used to compare participants with high versus low specialization on physical activity and movement quality. A Spearman correlation was used to determine the relationship between quantity of physical activity and movement quality, and linear regression was used to assess for the effect of participant age on relevant covariables. Results: Final analyses included 147 participants (72% male) with a mean ± SD age of 13.4 ± 2.2 years. Participants who were highly specialized displayed better movement quality than did participants with low sports specialization (27.6 ± 14.0 vs 19.8 ± 10.1; P < .01). Participants who were highly specialized had significantly higher activity levels (24.6 ± 5.9 vs 18.1 ± 6.9; P < .001). Movement quality was moderately correlated with physical activity level ( r = 0.335; P < .001). Physical activity; hours of organized sports activity; hours of free, unorganized physical activity; and specialization level were not significant predictors of movement quality when controlling for age. Age alone predicted 24.2% of the variance in the overall movement quality score ( R2 = 0.242; B = 3.0; P < .001). Conclusion: This study found that sports specialization and physical activity levels were not associated with movement quality when controlling for age, which was the most important variable predicting athletic movement quality. Although all participants displayed movement patterns that were associated with high risk for injury, overall movement quality improved with advancing chronological age. Clinical Relevance: All young athletes should ensure that neuromuscular training accompanies sport-specific training to reduce risk of injury.

The purpose of this study was to analyze the joint motion kinetics of the shoulders, elbows, and wrists between experienced player (skilled player) group and unskilled player group when performing overhead standing smash in badminton game. The samples involved were 26 samples. The samples included 13 male badminton players joining Student Activity Unit who had achieved many achievements and had a high skill (skilled), while the other 13 samples were unskilled players, involving students who had just studied under one year. The mean of participants’ age was 19.4 ± 1.6 years, height was 1.73 ± 0.12m, and body weight was 62.8 ± 3.7kg. This study used 3 Panasonic Handycams, a calibration set, 3D Frame DIAZ IV motion analysis software, and a speed radar gun. Normalization of the kinetic motion score of the shoulder, elbow, and wrist joints was calculated using the inverse dynamics method. The t-test was used to determine the significance of motion kinetic difference of the two different groups. The results presented that the shuttlecock speed of the skilled player group, during the overhead standing smash, showed a significant difference. Meanwhile, the joint motion of the inferior shoulder force, shoulder anterior force, shoulder internal rotation torque, shoulder horizontal abduction torque, elbow anterior force, and wrist flexion torque were higher in the skilled players group than the unskilled player group.