Requirements for upper extremity motions during activities of daily living

Assessing Shoulder Biomechanics of Healthy Elderly Individuals During Activities of Daily Living Using Inertial Measurement Units: High Maximum Elevation Is Achievable but Rarely Used

Current shoulder clinical range of motion (ROM) assessments (e.g., goniometric ROM) may not adequately represent shoulder function beyond controlled clinical settings. Relative inertial measurement unit (IMU) motion quantifies ROM precisely and can be used outside of clinic settings capturing "real-world" shoulder function. A novel IMU-based shoulder elevation quantification method was developed via IMUs affixed to the sternum/humerus, respectively. This system was then compared to in-laboratory motion capture (MOCAP) during prescribed motions (flexion, abduction, scaption, and internal/external rotation). MOCAP/IMU elevation were equivalent during flexion (R2 = 0.96, μError = 1.7 deg), abduction (R2 = 0.96, μError = 2.9 deg), scaption (R2 = 0.98, μError = -0.3 deg), and internal/external rotation (R2 = 0.90, μError = 0.4 deg). When combined across movements, MOCAP/IMU elevation were equal (R2 = 0.98, μError = 1.4 deg). Following validation, the IMU-based system was deployed prospectively capturing continuous shoulder elevation in 10 healthy individuals (4 M, 69 ± 20 years) without shoulder pathology for seven consecutive days (13.5 ± 2.9 h/day). Elevation was calculated continuously daily and outcome metrics included percent spent in discrete ROM (e.g., 0-5 deg and 5-10 deg), repeated maximum elevation (i.e., >10 occurrences), and maximum/average elevation. Average elevation was 40 ± 6 deg. Maximum with >10 occurrences and maximum were on average 145-150 deg and 169 ± 8 deg, respectively. Subjects spent the vast majority of the day (97%) below 90 deg of elevation, with the most time spent in the 25-30 deg range (9.7%). This study demonstrates that individuals have the ability to achieve large ROMs but do not frequently do so. These results are consistent with the previously established lab-based measures. Moreover, they further inform how healthy individuals utilize their shoulders and may provide clinicians a reference for postsurgical ROM.

Effect of Mechanically Passive, Wearable Shoulder Exoskeletons on Muscle Output During Dynamic Upper Extremity Movements: A Computational Simulation Study

Wearable passive (ie, spring powered) shoulder exoskeletons could reduce muscle output during motor tasks to help prevent or treat shoulder musculoskeletal disorders. However, most wearable passive shoulder exoskeletons have been designed and evaluated for static tasks, so it is unclear how they affect muscle output during dynamic tasks. The authors used a musculoskeletal model and Computed Muscle Control optimization to estimate muscle output with and without a wearable passive shoulder exoskeleton during 2 simulated dynamic tasks: abduction and upward reach. To an existing upper extremity musculoskeletal model, the authors added an exoskeleton model with 3-dimensional representations of the exoskeleton components, including a spring, cam wheel, force-transmitting shoulder cable, and wrapping surfaces that permitted the shoulder cable to wrap over the shoulder. The exoskeleton reduced net muscle-generated moments in positive shoulder elevation by 28% and 62% during the abduction and upward reach, respectively. However, muscle outputs (joint moments and muscle effort) were higher with the exoskeleton than without at some points of the movement. Muscle output was higher with the exoskeleton because the exoskeleton moment opposed the muscle-generated moment in some postures. The results of this study highlight the importance of evaluating muscle output for passive exoskeletons designed to support dynamic movements to ensure that the exoskeletons assist, rather than impede, movement.

Deep Learning-Based Upper Limb Functional Assessment Using a Single Kinect v2 Sensor

We develop a deep learning refined kinematic model for accurately assessing upper limb joint angles using a single Kinect v2 sensor. We train a long short-term memory recurrent neural network using a supervised machine learning architecture to compensate for the systematic error of the Kinect kinematic model, taking a marker-based three-dimensional motion capture system (3DMC) as the golden standard. A series of upper limb functional task experiments were conducted, namely hand to the contralateral shoulder, hand to mouth or drinking, combing hair, and hand to back pocket. Our deep learning-based model significantly improves the performance of a single Kinect v2 sensor for all investigated upper limb joint angles across all functional tasks. Using a single Kinect v2 sensor, our deep learning-based model could measure shoulder and elbow flexion/extension waveforms with mean CMCs >0.93 for all tasks, shoulder adduction/abduction, and internal/external rotation waveforms with mean CMCs >0.8 for most of the tasks. The mean deviations of angles at the point of target achieved and range of motion are under 5° for all investigated joint angles during all functional tasks. Compared with the 3DMC, our presented system is easier to operate and needs less laboratory space.

Assessment of Scapulothoracic, Glenohumeral, and Elbow Motion in Adhesive Capsulitis by Means of Inertial Sensor Technology: A Within-Session, Intra-Operator and Inter-Operator Reliability and Agreement Study

Adhesive capsulitis (AC) is a glenohumeral (GH) joint condition, characterized by decreased GH joint range of motion (ROM) and compensatory ROM in the elbow and scapulothoracic (ST) joint. To evaluate AC progression in clinical settings, objective movement analysis by available systems would be valuable. This study aimed to assess within-session and intra- and inter-operator reliability/agreement of such a motion capture system. The MVN-Awinda® system from Xsens Technologies (Enschede, The Netherlands) was used to assess ST, GH, and elbow ROM during four tasks (GH external rotation, combing hair, grasping a seatbelt, placing a cup on a shelf) in 10 AC patients (mean age = 54 (±6), 7 females), on two test occasions (accompanied by different operators on second occasion). Standard error of measurements (SEMs) were below 1.5° for ST pro-retraction and 4.6° for GH in-external rotation during GH external rotation; below 6.6° for ST tilt, 6.4° for GH flexion-extension, 7.1° for elbow flexion-extension during combing hair; below 4.4° for GH ab-adduction, 13° for GH in-external rotation, 6.8° for elbow flexion-extension during grasping the seatbelt; below 11° for all ST and GH joint rotations during placing a cup on a shelf. Therefore, to evaluate AC progression, inertial sensors systems can be applied during the execution of functional tasks.

Instrumented assessment of shoulder function: A study of inertial sensor based methods

BACKGROUND

Inertial sensors have the potential to provide objective and practical methods to assess joint and limb function in the clinical setting. The aim of this study is to evaluate the psychometric properties of inertial sensor metrics in the assessment of patients with subacromial shoulder pain.

METHODS

25 patients with unilateral subacromial shoulder pain and 50 control subjects were recruited. Assessments were carried out on both shoulders for all participants during a short movement procedure. Patients had assessments repeated after receiving three months of physiotherapy. Inertial metrics evaluated included a smoothness measure and speed and power scores derived from the range of angular velocity and acceleration profiles. Individual shoulder scores and asymmetry scores were both evaluated in terms of reliability, known-group validity, convergent validity and responsiveness.

FINDINGS

Regression analysis identified age to be a significant predictor for all scores, therefore an age matched sub-cohort of control subjects was used for comparative analyses. All scores demonstrated inter-rater reliability (ICC = 0.48-0.82), were able to differentiate pathological from healthy shoulders (AUC = 0.62-0.91) and displayed significant changes following treatment. Scores derived from the range of acceleration and velocity profiles demonstrated the largest effect sizes (Cohens d = 0.8-1.35), and displayed the highest correlation with the Oxford Shoulder Score (r = -0.40 - -0.58).

INTERPRETATION

The scores investigated demonstrate good psychometric properties and have potential to complement existing methods of assessment in the clinical or research setting. Further work is required to fully understand their clinical relevance and optimise assessment methods and interpretation.

Efficient Multiaxial Shoulder-Motion Tracking Based on Flexible Resistive Sensors Applied to Exosuits

This article describes the performance of a flexible resistive sensor network to track shoulder motion. This system monitors every gesture of the human shoulder in its range of motion except rotations around the longitudinal axis of the arm. In this regard, the design considers the movement of the glenohumeral, acromioclavicular, sternoclavicular, and scapulothoracic joints. The solution presented in this work considers several sensor configurations and compares its performance with a set of inertial measurement units (IMUs). These devices have been put together in a shoulder suit with Optitrack visual markers in order to be used as pose ground truth. Optimal configurations of flexible resistive sensors, in terms of accuracy requirements and number of sensors, have been obtained by applying principal component analysis techniques. The data provided by each configuration are then mapped onto the shoulder pose by using neural network algorithms. According to the results shown in this article, a set of flexible resistive sensors can be an adequate alternative to IMUs for multiaxial shoulder pose tracking in open spaces. Furthermore, the system presented can be easily embedded in fabric or wearable devices without obstructing the user's motion.

Design and wrench-feasible workspace analysis of a cable-driven hybrid joint

This article proposes a cable-driven hybrid joint (CDHJ), focuses on the effects of external wrench payload and structural parameters on the wrench-feasible workspace for the preliminary design of the mechanism, and further discusses the wrench exertion capability of the mechanism under a certain configuration. This CDHJ has central rigid support with a revolute pair and a central compression spring support. Due to the unilateral property of cables and the flexible compression spring, the kinematic model cannot define the workspace directly; it should be combined with the statics for possible solution, including the spring lateral buckling model based on the elliptic integral solution. Moreover, a global tension index which is to evaluate the wrench-closure property of the global workspace, combined with an index which is to assess the size of the workspace, is proposed to better compare the effects of different external wrench payloads and different structural parameters on the workspace. Simulations were performed and demonstrated the correctness and feasibility of the inverse kinematics and workspace analysis of the joint. Hence, the proposed mechanism has potential use in robotics especially in wheelchair-mounted robotic manipulator joint.

Kinematic profiles during activities of daily living in adults with traumatic brachial plexus injuries

BACKGROUND

Injuries to the brachial plexus leave individuals with lasting effects in upper extremity motor function, even with successful surgical restoration of elbow flexion. Quantitatively describing independent patient function during activities of daily living utilizing motion analysis could aid in prioritization of secondary surgical targets, as well as serve as an outcome measure. This study explored the upper extremity kinematic profiles during activities of daily living in adults with brachial plexus injury.

METHODS

Eight adult participants (4 subjects with brachial plexus injury, 4 healthy controls) completed activities of daily living during one motion capture setting. Trunk, shoulder, and elbow joint minima, maxima, and range of motion were calculated and compared between groups. Kinematic profiles over a motion cycle were compared between groups using statistical parametric mapping.

FINDINGS

Subjects with brachial plexus injuries had significantly greater trunk range of motion during feeding and dressing tasks compared to control subjects. This compensatory trunk motion was accompanied by limited shoulder external rotation demonstrated using conventional descriptors and statistical parametric mapping.

INTERPRETATION

Significant compensatory trunk motion is required to complete select activities of daily living in subjects with brachial plexus injury. Additionally, restoration of shoulder external rotation would be a beneficial secondary target of surgical restoration of motor function. These aspects should be considered in treatment planning, as they could impact patient outcomes. Combining conventional descriptors of patient motion (e.g. joint minima, maxima, and range of motion) with statistical parametric mapping can provide a rich description of patient compensations and limitations.

Relevance of grasp types to assess functionality for personal autonomy

STUDY DESIGN

Cross-sectional research design.

INTRODUCTION

Current assessment of hand function is not focused on evaluating the real abilities required for autonomy.

PURPOSE OF THE STUDY

To quantify the relevance of grasp types for autonomy to guide hand recovery and its assessment.

METHODS

Representative tasks of the International Classification of Functioning, Disability and Health activities in which the hands are directly involved were recorded. The videos were analyzed to identify the grasps used with each hand, and their relevance for autonomy was determined by weighting time with the frequency of appearance of each activity in disability and dependency scales. Relevance is provided globally and distinguished by hand (right-left) and bimanual function. Significant differences in relevance are also checked.

RESULTS

The most relevant grasps are pad-to-pad pinch (31.9%), lumbrical (15.4%), cylindrical (12%), and special pinch (7.3%) together with the nonprehensile (18.6%) use of the hand. Lumbrical grasp has higher relevance for the left hand (19.9% vs 12%) while cylindrical grasp for the right hand (15.3% vs 7.7%). Relevancies are also different depending on bimanual function.

DISCUSSION

Different relative importance was obtained when considering dependency vs disability scales. Pad-to-pad pinch and nonprehensile grasp are the most relevant grasps for both hands, whereas lumbrical grasp is more relevant for the left hand and cylindrical grasp for the right one. The most significant difference in bimanual function refers to pad-to-pad pinch (more relevant for unimanual actions of the left hand and bimanual actions of the right).

CONCLUSIONS

The relative importance of each grasp type for autonomy and the differences observed between hand and bimanual action should be used in medical and physical decision-making.

LEVEL OF EVIDENCE

N/A.

Simplifying Exosuits: Kinematic Couplings in the Upper Extremity during Daily Living Tasks

In the past few years, several light-weight soft wearable robots, so called exosuits, for upper extremity assistance have been developed. The design of exosuits is often based on a bio-mimetic design approach, mimicking the human biomechanics. However, in the design process, the interactions of movement directions during daily living tasks have not yet been analyzed comprehensively. Therefore, the designs of exosuits might be overly complex, as movement directions that are coupled during daily life tasks were implemented independently; or lack functionality, as relevant movement directions were disregarded. In the meta-analysis presented in this paper, the maximum angles occurring during daily living tasks in the upper extremity of unimpaired individuals were examined. To identify the kinematic couplings between joint axes, the interactions between movement directions that act against gravity were analyzed. The strongest correlations were found between rotation in the plane of elevation and humeral axial rotation ($R^{2} = 0.82$, p < 0.001), and between humeral elevation and humeral axial rotation $(R^{2}\ =\ 0.16,\ p=\ 0.001)$. Shoulder rotations and elbow flexion were not correlated. We conclude that humeral axial rotation is a relevant movement direction in the upper extremity, which, so far, has often been neglected in the design of exosuits. To simplify the design of exosuits, we propose a one degree of freedom support trajectory in which rotation in the plane of elevation (at -70° and 80°) and humeral axial rotation (at 110° and -60°) are coupled to humeral elevation (continuously from -40° to -110°).

Continuously monitoring shoulder motion after total shoulder arthroplasty: maximum elevation and time spent above 90° of elevation are critical metrics to monitor

BACKGROUND

Traditional clinical shoulder range-of-motion (ROM) measurement methods (ie, goniometry) have limitations assessing ROM in total shoulder arthroplasty (TSA) patients. Inertial measurement units (IMUs) are superior; however, further work is needed using IMUs to longitudinally assess shoulder ROM before TSA and throughout post-TSA rehabilitation. Accordingly, the study aims were to prospectively capture shoulder elevation in TSA patients and to compare the results with healthy controls. We hypothesized that patients would have reduced maximum elevation before TSA compared with controls but would have improved ROM after TSA.

METHODS

A validated IMU-based shoulder elevation quantification method was used to continuously monitor 10 healthy individuals (4 men and 6 women; mean age, 69 ± 20 years) without shoulder pathology and 10 TSA patients (6 men and 4 women; mean age, 70 ± 8 years). Controls wore IMUs for 1 week. Patients wore IMUs for 1 week before TSA, for 6 weeks at 3 months after TSA, and for 1 week at 1 year after TSA. Shoulder elevation was calculated continuously, broken into 5° angle "bins" (0°-5°, 5°-10°, and so on), and converted to percentages. The main outcome measures were binned movement percentage, maximum elevation, and average elevation. Patient-reported outcome measures and goniometric ROM were also captured.

RESULTS

No demographic differences were noted between the cohorts. Average elevation was not different between the cohorts at any time. Control maximum elevation was greater than pre-TSA and post-TSA week 1 and week 2 values. Time under 30° and time above 90° were equal between the cohorts before TSA. After TSA, patients showed decreased time under 30° and increased time above 90°.

DISCUSSION

This study demonstrates that acute and chronic recovery after TSA can be assessed via maximum elevation and time above 90°, respectively. These results inform how healthy individuals and patients use their shoulders before and after TSA.

Derotational Pronation-producing Osteotomy of the Radius and Biceps Tendon Rerouting for Supination Contractures in Neonatal Brachial Plexus Palsy Patients: A Review of 20 Cases

BACKGROUND

Forearm supination contractures can occur as a result of neurological derangement of the upper extremity in patients with neonatal brachial plexus birth palsy. The contractures become problematic in childhood as patients begin requiring forearm pronation for activities of daily living including typing on a keyboard and writing. There have been several techniques described to remedy this deformity. We present a case series describing the early clinical results of combined radial osteotomy and intraosseous biceps rerouting to realign the forearm in resting pronation and convert the biceps from a supinator to a pronator.

METHODS

A retrospective review identified patients who had a radial osteotomy and biceps rerouting for supination contracture between 2006 and 2016. Inclusion criteria required a fixed forearm supination contracture, patients below 18 years of age and at least 1 year of clinical and radiographic follow-up. Demographic and surgical variables, early clinical results, complications, reoperations, and revisions were documented.

RESULTS

Twenty patients were identified who met inclusion criteria. The mean follow-up was 3 years (range, 1 to 9 y). We observed a statistically significant difference in the mean resting position of the forearm from 56 degrees of supination preoperatively to 17 degrees of pronation postoperatively. Correspondingly, there was an increase in passive forearm pronation from 0 degree preoperatively to 66 degrees postoperatively and an expected decrease in passive forearm supination from 78 degrees preoperatively to 41 degrees postoperatively. There were 2 complications which were both radial osteotomy nonunions. Excluding revisions, there were 14 reoperations in 14 patients (63%) for hardware removal. Hardware removal was considered an expected return to the operating room, not an unplanned reoperation. There were 2 revisions for osteotomy nonunion, both of which went on to eventual union. Overall survivorship from the need for revision surgery was 95% at 12 months, 88% at 24 months, and 88% at 60 months. There were no recurrences of the supination contracture.

CONCLUSIONS

We present results of a novel surgical solution to forearm supination contractures through the combination of a derotational osteotomy of the radius and biceps tendon rerouting. The results show a significant benefit in forearm positioning and passive pronation with excellent survivorship and maintenance of correction.

LEVEL OF EVIDENCE

Level IV-therapeutic.

Functional range of motion in the upper extremity and trunk joints: Nine functional everyday tasks with inertial sensors

BACKGROUND

Functional range of motion is defined as the required range of motions for individuals to maintain maximal independence, along with optimal conditions for activities of daily living. Intervention plans for rehabilitation are directed towards the acquisition of anatomical range of motion. However, this isn't always possible based on person's etiology, prognosis, or severity of disease.

RESEARCH QUESTION

The aim of this study is to determine functional range of motion during different unilateral, bilateral symmetrical and bimanual asymmetrical tasks of activities of daily living.

METHODS

Participants completed nine basic activities of daily living (hand to head, hanging jacket, eating, wallet placement to back pocket, washing hands and face, removing belt, water pouring, brushing teeth) linked according to International Classification of Functioning, Disability and Health, while joint kinematics of the trunk and upper extremity were recorded with inertial measurement units. Peak values of mean joint angles were determined for each activities of daily living. MVN BIOMECH Awinda MTW2-3A7G6 sensors (Xsens Technologies B.V. Enschede, Netherlands) were used for 3D kinematic analysis of activities.

RESULTS

Forty-six healthy subjects (right-dominant) were included in this study. Range of motion requirements of all activities were defined 37.85° extension, 91.18° flexion, 1.25° adduction, 39.45° abduction, 63.6° internal rotation, 21.8° external rotation in the dominant shoulder, 124.17° flexion in the dominant elbow, 40.29° extension, 23.66° flexion, 18.31° supination, 12.56° pronation, 18.27 ulnar deviation and, 18.36° radial deviation in the dominant wrist. Maximum trunk range of motions were found to be 29.75° flexion in C7-T1, 10.74° flexion in T12-L1, and 24.16° flexion in L5-S1.

SIGNIFICANCE

It is thought that the results of this research will contribute to the determination of normative data needed for surgical interventions, technological rehabilitation devices and task-spesific rehabilitation programs which based patient's motor skill level.

Dispersion of helical axes during shoulder movements in young and elderly subjects

The shoulder complex (SC) consists of joints with little congruence and its active and passive structures ensure its stability. Stability of the SC rotation centre during upper arm movements can be estimated through the analysis of Helical Axes (HAs) dispersion. The aim of this study was to describe shoulder HAs dispersion during upper limb movements performed with dominant and non-dominant arms by young and elderly subjects. Forty subjects participated in the study (20 young: age 24.8 ± 2.8 years and 20 elderly: age 71.7 ± 6.3 years). Subjects were asked to perform four cycles of 15 rotations, flexions, elevations and abductions with one arm at a time at constant speed. Reflective markers were placed on participants' arms and trunk in order to detect movements and the HAs dispersion with an optoelectronic system. Mean Distance (MD) from the HAs barycenter and Mean Angle (MA) were used as HAs dispersion indexes. Young subjects showed significant lower MD compared to the elderly during all motion ranges of rotation, flexion and elevation (p < 0.001). Moreover, the MD was lower in the dominant arm compared to the contralateral for rotation (p = 0.049) and flexion (p = 0.019). The results may be due to joint degeneration described in elderly subjects and differences in neuromuscular control of SC stability.

Kinect-Assisted Performance-Sensitive Upper Limb Exercise Platform for Post-stroke Survivors

One's ability to use upper limbs is critical for performing activities of daily living necessary for enjoying quality community life. However, after stroke, such abilities becomes adversely affected and it often deprives one of their capability to perform tasks that need coordinated movement in the upper limbs. To address issues with upper limb dysfunction, patients typically undergo rehabilitative exercises. Given the high patient to doctor ratio particularly in developing countries like India, conventional rehabilitation with patients undergoing exercises under one-on-one therapist's supervision often becomes a challenge. Thus, investigators are exploring technology such as computer-based platforms coupled with cameras that can alleviate the need for the continuous presence of a therapist and can offer a powerful complementary tool in the hands of the clinicians. Such marker-based imaging systems used for rehabilitation can offer real-time processing and high accuracy of data. However, these systems often require dedicated lab space and high set-up time. Often this is very expensive and suffers from portability issues. Investigators have been exploring marker-less imaging techniques e.g., Kinect integrated computer-based graphical user interfaces in stroke-rehabilitation such as tracking one's limb movement during rehabilitation. In our present study, we have developed a Kinect-assisted computer-based system that offered Human Computer Interaction (HCI) tasks of varying challenge levels. Execution of the tasks required one to use reaching and coordination skills of the upper limbs. Also, the system was Performance-sensitive i.e., adaptive to the individualized residual movement ability of one's upper limb quantified in terms of task performance score. We tested for the usability of our system by exposing 15 healthy participants to our system. Subsequently, seven post-stroke patients interacted with our system over a few sessions spread over 2 weeks. Also, we studied patient's mean tonic activity corresponding to the HCI tasks as a possible indicator of one's post-stroke functional recovery suggesting its potential of our system to serve as a rehabilitation platform. Our results indicate the potential of such systems toward the improvement of task performance capability of post-stroke patients with possibilities of upper limb movement rehabilitation.

Influence of humeral abduction angle on axial rotation and contact area at the glenohumeral joint

BACKGROUND

Although the elevation angle of the arm affects the range of rotation, it has not been evaluated up to the maximal abduction angle. In this study we conducted an evaluation up to maximal abduction and determined the contact patterns at the glenohumeral (GH) joint.

METHODS

Fourteen healthy volunteers (12 men and 2 women; mean age, 26.9 years) with normal shoulders (14 right and 8 left) were instructed to rotate their shoulders at 0°, 90°, 135°, and maximal abduction for each shoulder at a time. Using 2-dimensional and 3-dimensional single-plane image registration, the internal rotation (IR), external rotation (ER), and range of motion (ROM; ie, axial rotations) at the thoracohumeral (TH) and GH joints, and the contribution ratio (%ROM = GH-ROM/TH-ROM) were calculated for each abduction. The glenoid position with respect to the humeral head was also analyzed.

RESULTS

The TH-IR and TH-ER shifted toward an ER with increasing abduction angle, whereas the TH-ROM significantly decreased except at abduction between 0° and 90° (P < .001). The GH-IR and GH-ROM significantly decreased except at abduction between 0° and 90° (P < .001), but the GH-ER remained constant regardless of the abduction. The contribution ratio exceeded 80% for every abduction angle. The glenoid moved on the central and posterior areas of the humeral head at 0° and 90° abduction, respectively, and on the posterosuperior and anterosuperior areas at 135° and maximal abduction, respectively.

CONCLUSION

Our results provide new knowledge about wide axial rotation up to maximal abduction and constant GH-ER at any abduction.

Modular Design and Decentralized Control of the Recupera Exoskeleton for Stroke Rehabilitation

Robot-assisted therapy has become increasingly popular and useful in post-stroke neurorehabilitation. This paper presents an overview of the design and control of the dual-arm Recupera exoskeleton to provide intense therapist-guided as well as self training for sensorimotor rehabilitation of the upper body. The exoskeleton features a lightweight design, high level of modularity, decentralized computing, and various levels of safety implementation. Due to its modularity, the system can be used as a wheel-chair mounted system or as a full-body system. Both systems enable a wide range of therapies while efficiently grounding the weight of the system and without compromising the patient’s mobility. Furthermore, two rehabilitation therapies implemented on the exoskeleton system, namely teach & replay therapy and mirror therapy, are presented along with experimental results.

A survey of human shoulder functional kinematic representations

In this survey, we review the field of human shoulder functional kinematic representations. The central question of this review is to evaluate whether the current approaches in shoulder kinematics can meet the high-reliability computational challenge. This challenge is posed by applications such as robot-assisted rehabilitation. Currently, the role of kinematic representations in such applications has been mostly overlooked. Therefore, we have systematically searched and summarised the existing literature on shoulder kinematics. The shoulder is an important functional joint, and its large range of motion (ROM) poses several mathematical and practical challenges. Frequently, in kinematic analysis, the role of the shoulder articulation is approximated to a ball-and-socket joint. Following the high-reliability computational challenge, our review challenges this inappropriate use of reductionism. Therefore, we propose that this challenge could be met by kinematic representations, that are redundant, that use an active interpretation and that emphasise on functional understanding.

Rating scales for shoulder and elbow range of motion impairment: Call for a functional approach

Background

To evaluate the effect of (new) treatments or analyse prevalence and risk factors of contractures, rating scales are used based on joint range of motion. However, cut-off points for levels of severity vary between scales, and it seems unclear how cut-off points relate to function. The purpose of this study was to compare severity ratings of different rating scales for the shoulder and elbow and relate these with functional range of motion.

Methods

Often used contracture severity rating scales in orthopedics, physiotherapy, and burns were included. Functional range of motion angles for the shoulder and elbow were derived from a recent synthesis published by our group. Shoulder flexion and elbow flexion range of motion data of patients three months after a burn injury were rated with each of the scales to illustrate the effects of differences in classifications. Secondly, the shoulder and elbow flexion range of motion angles were related to the required angles to perform over 50 different activities of daily living tasks.

Results

Eighteen rating scales were included (shoulder: 6, elbow: 12). Large differences in the number of severity levels and the cut-off points between scales were determined. Rating the measured range of motions with the different scales showed substantial inconsistency in the number of joints without impairment (shoulder: 14–36%, elbow: 26–100%) or with severe impairment (shoulder: < 10%–29%, elbow 0%–17%). Cut-off points of most scales were not related to actual function in daily living.

Conclusion

There is an urgent need for rating scales that express the severity of contractures in terms of loss of functionality. This study proposes a direction for a solution.

Simulated activities of daily living do not replicate functional upper limb movement or reduce movement variability

Kinematic assessments of the upper limb during activities of daily living (ADLs) are used as an objective measure of upper limb function. The implementation of ADLs varies between studies; whilst some make use of props and define a functional target, others use simplified tasks to simulate the movements in ADLs. Simulated tasks have been used as an attempt to reduce the large movement variability associated with the upper limb. However, it is not known whether simulated tasks replicate the movements required to complete ADLs or reduce movement variability. The aim of this study is to evaluate the use of simulated tasks in upper limb assessments in comparison to functional movements. Therefore answering the following questions: Do simulated tasks replicate the movements required of the upper limb to perform functional activities? Do simulated tasks reduce intra- and inter-subject movement variability? Fourteen participants were asked to perform five functional tasks (eat, wash, retrieve from shelf, comb and perineal care) using two approaches: a functional and a simulated approach. Joint rotations were measured using an optoelectronic system. Differences in movement and movement variability between functional and simulated tasks were evaluated for the thorax, shoulder, elbow/forearm and wrist rotations. Simulated tasks did not accurately replicate the movements required for ADLs and there were minimal differences in movement variability between the two approaches. The study recommends the use of functional tasks with props for future assessments of the upper limb.

Simulation of bone-determined range of motion in proximal humeral fractures

BACKGROUND

Predicting the outcome following fractures of the proximal humerus is an important consideration when effectively counselling patients and planning treatment. The purpose of the present study was to analyze different proximal humeral fracture configurations, using a computerized simulation model, aiming to predict the range of motion (ROM).

METHODS

The computer tomography scans of 79 proximal humeral fractures were analyzed using a customized software system that simulated the range of movement at the glenohumeral joint. Four fracture patterns were investigated: (1) head split fractures; (2) greater tuberosity fractures; (3) lesser tuberosity fractures; and (4) combined tuberosity fractures.

RESULTS

Intra-articular fractures had the smallest mean (SE) range of abduction and forward flexion [34.3° (6.6°) and 60.7° (12.4°)]. Isolated displaced greater tuberosity resulted in limited abduction but not forward flexion [75.0° (5.9°) and 118.2° (4.9°)]. Isolated lesser tuberosity fractures displayed a ROM comparable to that of healthy subjects [89.3° (3.3°) and 122.6° (3.4°) versus 102.3° (2.8°) and 96.2° (3.8°)]. The reduced head inclination angle was a relatively strong predictor of a limited range of abduction for all fracture types.

CONCLUSIONS

The present study describes a novel simulation system used to quantify the bone-determined ROM in proximal humeral fractures and may be a useful adjunct in the diagnostic armamentarium for proximal humeral fractures.

Examining upper limb kinematics and dysfunction of breast cancer survivors in functional dynamic tasks

BACKGROUND

Comorbidities within the breast cancer population can reduce quality of life. Current breast cancer survivor upper limb kinematic strategies unfortunately lack robust connection with performing important activities of daily living.

METHODS

Accordingly, fifty breast cancer survivors performed 88 dynamic tasks (divided into range of motion-reach, range of motion-rotate, activity of daily living, and work tasks). Humerothoracic and scapulothoracic angles were extracted from motion capture data. Bilateral differences existed for range of motion, and maximal and minimal scapulothoracic and humerothoracic angles.

FINDINGS

Generally, the affected side used less range of motion across task types. Humerothoracic angles on the affected side experienced 6.7° less range of motion in plane of elevation in range of motion-reach (p < 0.01), 2.3° less elevation angle range of motion in range of motion-rotate (p = 0.01), and 7.1° more internal rotation range of motion in range of motion-rotate (p < 0.01). Scapulothoracic angles on the affected side had 2° more anterior/posterior tilt range of motion in work tasks (p = 0.03), 3.4° less maximal protraction in activity of daily living tasks (p = 0.01), and 3.5° less minimum downward rotation in range of motion-rotate (p < 0.01).

INTERPRETATION

A reduced range of motion on the affected side suggests the breast cancer population had less varied movement strategies, keeping movements in narrower ranges to avoid disability, pain, or subacromial impingement. This investigation produced an unprecedentedly diverse collection of three-dimensional humerothoracic and scapulothoracic kinematics for a breast cancer population. Documentation of physical capability, dysfunction, and adaptive strategies is a crucial step towards developing targeted strategies for enhancing functional recovery in breast cancer survivors.

Teres major tendon transfer in the treatment of irreparable posterosuperior rotator cuff tears: long-term improvement of shoulder function and pain reduction at eight to 12 years’ follow-up

Aims

Since long-term outcome of teres major tendon transfer surgery for irreparable posterosuperior rotator cuff (RC) tears is largely unknown, the primary aim of this study was to evaluate the long-term outcome of the teres major transfer. We also aimed to report on the results of a cohort of patients with a similar indication for surgery that underwent a latissimus dorsi tendon transfer.

Patients and Methods

Patients and Methods In this prospective cohort study, we reported on the long-term results of 20 consecutive patients with a teres major tendon transfer for irreparable massive posterosuperior RC tears. Additionally, we reported on the results of the latissimus dorsi tendon transfer (n = 19). The mean age was 60 years (47 to 77). Outcomes included the Constant score (CS), and pain at rest and during movement using the Visual Analogue Scale (VAS).

Results

At a mean of ten years (8 to 12) following teres major transfer, the CS was still 23 points (95% confidence interval (CI) 14.6 to 30.9, p < 0.001) higher than preoperatively. VAS for pain at rest (21 mm, 95% CI 4.0 to 38.9, p = 0.016) and movement (31 mm, 95% CI 16.0 to 45.1, p < 0.001) were lower than preoperatively. We also found an increase in CS (32 points, 95% CI 23.4 to 40.2, p < 0.001) and reduction of pain (26 mm, 95% CI 9.9 to 41.8, p = 0.001) six years after latissimus dorsi transfer.

Conclusion

Teres major tendon transfer is a treatment option to gain shoulder function and reduce pain in patients with an irreparable posterosuperior RC tear at a mean follow-up of ten years. The teres major tendon might be a valuable alternative to the commonly performed latissimus dorsi tendon transfer in the treatment of irreparable posterosuperior RC tears. Cite this article: Bone Joint J 2018;100-B:309-17.

A soft wearable robot for the shoulder: Design, characterization, and preliminary testing

In this paper, we present a soft wearable robot for the shoulder which has the potential to assist individuals suffering from a range of neuromuscular conditions affecting the shoulder to perform activities of daily living. This wearable robot combines two types of soft textile pneumatic actuators which were custom developed for this particular application to support the upper arm through shoulder abduction and horizontal flexion/extension. The advantage of a textile-based approach is that the robot can be lightweight, low-profile, comfortable and non-restrictive to the wearer, and easy to don like an item of clothing. The actuator's ability to fold flat when not in use allows the robot to be almost invisible under clothing, potentially allowing the user to avoid any stigma associated with using assistive devices in public. To abduct the arm, a textilebased pneumatic actuator was developed to fit within the axilla to push the arm upwards, while a pair of smaller actuators pivot the abduction actuator to allow for horizontal extension and flexion. The individual textile actuators were experimentally evaluated before being integrated into a wearable garment. Human subject testing was performed to evaluate the ability of the robot to assist the arm by monitoring changes in biological muscle activity when comparing the robot powered on and off. Preliminary results show large reductions in muscular effort in targeted muscles, demonstrating the feasibility and promise of such a soft wearable robot for the shoulder.

MoBio: A 5 DOF trans-humeral robotic prosthesis

In this paper, a 5 DOF trans-humeral robotic prosthesis: MoBio is proposed. MoBio includes 2 DOF at wrist which is rare in other trans-humeral prostheses. Through anthropometric features MoBio prosthetic arm can achieve elbow flexion/extension, forearm supination/pronation, wrist radial/ulnar deviation, wrist flexion/extension and compound motion of thumb and index finger. An EMG based control method which uses EMG signals of the biceps brachii and triceps brachii, is used with a motion switching mechanism to control the prosthesis. Experimental results have verified the usability and effectiveness of MoBio in performing Activities of Daily Living.

The Unsupported Upper Limb Exercise Test in People Without Disabilities: Assessing the Within-Day Test-Retest Reliability and the Effects of Age and Gender

Purpose: To estimate the within-day test-retest reliability and standard error of measurement (SEM) of the unsupported upper limb exercise test (UULEX) in adults without disabilities and to determine the effects of age and gender on performance of the UULEX. Method: A cross-sectional study was conducted with 100 adults without disabilities (44 men, mean age 44.2 [SD 26] y; 56 women, mean age 38.1 [SD 24.1] y). Participants performed three UULEX tests to establish within-day reliability, measured using an intra-class correlation coefficient (ICC) model 2 (two-way random effects) with a single rater (ICC[2,1]) and SEM. The effects of age and gender were examined using two-factor mixed-design analysis of variance (ANOVA) and one-way repeated-measures ANOVA. For analysis purposes, four sub-groups were created: younger adults, older adults, men, and women. Results: Excellent within-day reliability and a small SEM were found in the four sub-groups (younger adults: ICC[2,1]=0.88; 95% CI: 0.82, 0.92; SEM∼40 s; older adults: ICC[2,1]=0.82; 95% CI: 0.72, 0.90; SEM∼50 s; men: ICC[2,1]=0.93; 95% CI: 0.88, 0.96; SEM∼30 s; women: ICC[2,1]=0.85; 95% CI: 0.78, 0.91; SEM∼45 s). Younger adults took, on average, 308.24 seconds longer than older adults to perform the test; older adults performed significantly better on the third test (p<0.0001; η²=0.096). Gender effects were not found (p>0.05). Conclusion: The within-day test-retest reliability and SEM values of the UULEX may be used to define the magnitude of the error obtained with repeated measures. One UULEX test seems to be adequate for younger adults to achieve reliable results, whereas three tests seem to be needed for older adults.

Quantification of upper limb electromyographic measures and dysfunction of breast cancer survivors during performance of functional dynamic tasks

BACKGROUND

Upper limb morbidities within the breast cancer population can interfere with completing daily life activities. Current knowledge of upper limb capabilities is limited; previous increases in muscle activation on the affected cancer side suggest this population works at a higher fraction of their capability. The purposes of this study were to describe upper limb capabilities and dysfunction of breast cancer survivors through muscle activation monitoring via surface electromyography and muscle-specific strength tests during functional tasks.

METHODS

Fifty survivors performed 88 dynamic tasks (divided into range of motion-reach or rotate, activities of daily life and work tasks). Muscle activation was examined for functional and strength testing tasks.

FINDINGS

Total muscle effort (summation of integrated electromyography across measured muscles) was up to 5.1% greater on the affected side during work tasks (p=0.0258). Increased activations existed in posterior deltoid, supraspinatus, upper trapezius and serratus anterior (p<0.05) for several tasks, including daily living tasks. Reduced activation occurred in affected pectoralis major sternal during all tasks (p<0.0001-0.0032), and affected infraspinatus in all but daily living tasks (p=0.0002-0.0328). The affected side infraspinatus, supraspinatus and upper trapezius muscles demonstrated significant reductions in targeted strength testing (p=0.0001-0.0057).

INTERPRETATION

Both primary and secondary muscles (outside surgery and radiation fields) were affected. In general, this population works at higher levels of muscle effort for the affected side yet demonstrates weakness in strength testing, which may reflect tissue damage. Strengthening exercises for the posterior rotator cuff and upper trapezius may be the most beneficial.

Oberlin transfer compared with nerve grafting for improving early supination in neonatal brachial plexus palsy

OBJECTIVE The use of nerve transfers versus nerve grafting for neonatal brachial plexus palsy (NBPP) remains controversial. In adult brachial plexus injury, transfer of an ulnar fascicle to the biceps branch of the musculocutaneous nerve (Oberlin transfer) is reportedly superior to nerve grafting for restoration of elbow flexion. In pediatric patients with NBPP, recovery of elbow flexion and forearm supination is an indicator of resolved NBPP. Currently, limited evidence exists of outcomes for flexion and supination when comparing nerve transfer and nerve grafting for NBPP. Therefore, the authors compared 1-year postoperative outcomes for infants with NBPP who underwent Oberlin transfer versus nerve grafting. METHODS This retrospective cohort study reviewed patients with NBPP who underwent Oberlin transfer (n = 19) and nerve grafting (n = 31) at a single institution between 2005 and 2015. A single surgeon conducted intraoperative exploration of the brachial plexus and determined the surgical nerve reconstruction strategy undertaken. Active range of motion was evaluated preoperatively and postoperatively at 1 year. RESULTS No significant difference between treatment groups was observed with respect to the mean change (pre- to postoperatively) in elbow flexion in adduction and abduction and biceps strength. The Oberlin transfer group gained significantly more supination (100° vs 19°; p < 0.0001). Forearm pronation was maintained at 90° in the Oberlin transfer group whereas it was slightly improved in the grafting group (0° vs 32°; p = 0.02). Shoulder, wrist, and hand functions were comparable between treatment groups. CONCLUSIONS The preliminary data from this study demonstrate that the Oberlin transfer confers an advantageous early recovery of forearm supination over grafting, with equivalent elbow flexion recovery. Further studies that monitor real-world arm usage will provide more insight into the most appropriate surgical strategy for NBPP.

Upper-limb motor and sensory function in patients with hip fracture: Comparison with community-dwelling older adults

BACKGROUND

Upper-limb function is important in patients with hip fracture so they can perform activities of daily living and participate in leisure activities. Upper-limb function of these patients, however, has not been thoroughly investigated.

OBJECTIVE

The aim of this study was to evaluate the upper-limb motor and sensory functions in patients with hip fracture by comparing these functions with those of community-dwelling older adults (control group).

METHODS

We compared the results of motor and sensory function tests of upper-limb function - range of motion, strength, sensibility, finger dexterity, comprehensive hand function - between patients with hip fracture (n= 32) and the control group (n= 32).

RESULTS

Patients with hip fracture had significantly reduced grip strength, pinch strength, finger dexterity, and comprehensive hand function compared with the control group.

CONCLUSIONS

Most upper-limb functions are impaired in the patients with hip fracture. Thus, upper-limb function of patients with hip fracture should be considered during treatment.

Supination Contractures in Brachial Plexus Birth Palsy: Long-Term Upper Limb Function and Recurrence After Forearm Osteotomy or Nonsurgical Treatment

PURPOSE

Forearm osteotomy for supination deformity in brachial plexus birth palsy (BPBP) may lead to improved function of the upper limb. However, recurrence rates are high and limit satisfactory results.

METHODS

We reviewed the long-term outcome of the entire upper limb of 22 BPBP patients with a supination contracture who were treated by forearm osteotomy and compared them with an age-matched group that was treated nonsurgically (n = 28). Recurrence was defined as a passive pronation below 30°.

RESULTS

The median follow-up was 5.0 years (range, 1.5-14 years). The mean passive pronation after forearm osteotomy, including patients with recurrence at follow-up, improved from -1° (SD, 9°) to 33° (SD, 48°) at final follow-up, mean active wrist extension improved from 23° (SD, 40°) to 41° (SD, 38°). An overall improvement of wrist and hand strength was present. In patients without recurrence, pronation improved to a mean of 66° (SD, 23°) at final follow-up. Recurrence of the supination contracture was present in 9 cases (41%) and was only present in patients with a single bone osteotomy. Recurrence was associated with lower age at surgery (recurrence mean, 4 [SD, 1.2] and no recurrence 8 [SD 4.5]), lower shoulder external rotation (recurrence mean, 28 [SD, 17] and no recurrence 49 [SD, 23]), and overall lower hand function at baseline.

CONCLUSIONS

Forearm osteotomy improves forearm pronation and hand function. Recurrence should be considered as a potential complication after forearm osteotomy and is associated with young age and lower function of shoulder and hand. Single-bone osteotomy might also be a risk factor for recurrence.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

FUNCTION AND BIOMECHANICS OF UPPER LIMB IN POST-STROKE PATIENTS — A SYSTEMATIC REVIEW

Current clinical services are struggling to provide the most favorable rehabilitation treatment for patients with stroke, which inspired researchers to investigate and explore the use of rehabilitation devices suitable for the patients and rehabilitation therapy. This review paper addresses the importance of biomechanical features in patients who experienced stroke to the upper limb. First and foremost, a review was done on general biomechanical description associated with motor control, shoulder, elbow, wrist and fingers joint. This included the ability of the patients to move their affected arm and the affect on peak joint torque, range of motion, joint forces, grip strength and muscle activities during the activities of daily living. In addition, we also reviewed the material properties and geometrical condition of tissue in stroke patient. The repercussions of post-stroke patient regarding the bone density, stiffness of muscle as well as the thickness of cartilage are described in this review. Based on the findings, the movement of affected stroke hand is associated with the motor control and material properties of tissue. To strengthen the motor control and maintaining tissue properties, early physical training on patients should be conducted in two to four weeks after stroke. In conclusion, this report suggests a new approach for future biomechanical studies in order to enhance the quality of physiotherapy rehabilitation peculiarly for post-stroke patients.

Influence of Gender Differences on Range of Motion and Joint Angles During Eating in Young, Healthy Japanese Adults

Objective

Eating is important in rehabilitation and is evaluated using joint angles that serve as kinematic information. Joint angles of the upper extremities during eating have been reported for men and for women; however, no study has investigated these joint angles in terms of gender differences. At present, no information is available on gender differences as individual factors of upper extremity joint angles during eating. Therefore, the present study investigated gender differences in upper limb joint angles during eating tasks involving a spoon or chopsticks.

Methods

We examined eating motions in 12 healthy Japanese men and 13 healthy Japanese women (aged 20-39 years) and compared the two groups. Motions were assessed using inertial sensors and three-dimensional motion analysis.

Results

We established, separately for men and women, the maximum angle and the range of motion (RoM) for each upper limb joint. Women generally had greater RoMs for all upper limb joints than men did. When subjects used a spoon, statistically significant differences and large effect sizes were observed for the maximum elbow joint flexion angle and the RoMs of the shoulder joint in abduction, flexion, and internal rotation. When subjects used chopsticks, statistically significant differences and large effect sizes were observed for maximum angles of shoulder joint internal rotation, elbow joint flexion, and wrist joint radial flexion and for the RoM of shoulder joint abduction.

Conclusions

We concluded that there are significant gender differences in upper limb joint angles during eating, and that these differences are influenced by numerous factors.

Bilateral changes in 3-D scapular kinematics in individuals with chronic stroke

BACKGROUND

Stroke can lead to altered scapular motion that may limit the ability to perform activities of daily living. The aims were to evaluate scapular kinematics of individuals with chronic stroke and the correlation with paretic arm function.

METHODS

Scapular kinematics was assessed in thirty-four individuals (Chronic stroke=17; controls=17) during arm elevation and lowering in scapular and self-selected planes, and during hair combing. The use of the paretic arm to perform activities of daily living was assessed by the Motor Activity Log (MAL-30). Scapular kinematics was compared among paretic and non-paretic arms, and controls. Correlation between scapular kinematics and MAL-30 was also verified.

FINDINGS

Paretic and non-paretic arms showed increased scapular internal rotation (p<0.05) during arm lowering in the scapular plane, and during arm elevation and lowering in the self-selected plane compared to controls. Increased internal rotation (p<0.05) was also found in the paretic arm during hair combing compared to controls. Increased scapular anterior tilt (p<0.05) was observed in the paretic arm during arm elevation while performing the activity of hair combing and during arm elevation and lowering in the scapular and self-selected planes compared to controls. The non-paretic arm showed increased anterior tilt (p<0.05) during arm elevation and lowering in self-selected plane compared to controls. No difference in scapular upward rotation among neither arms, nor correlation between scapular kinematics and MAL-30 were found (p>0.05).

INTERPRETATION

Individuals with chronic stroke showed bilateral scapular kinematics alterations. However, these alterations are not correlated with paretic arm function.

Early Development and Reliability of the Timed Functional Arm and Shoulder Test

Study Design Repeated-measures clinical measurement reliability study. Background While there are some shoulder functional tests for athletes, no widely used performance test of arm and shoulder function currently exists to assess lower-level upper extremity functional demands in, for example, a nonathlete population or elderly individuals. In these individuals, functional measures rely on patient self-report. Objectives Describe the development of the Timed Functional Arm and Shoulder Test (TFAST), age-related scores, and between-session reliability in a group of asymptomatic high school athletes, young adults, middle-aged adults, older adults, and a preliminary group of symptomatic patients. Methods One hundred forty asymptomatic individuals participated in the study: 36 high school athletes (14-18 years of age), 34 young adults (19-35 years of age), 37 middle-aged adults (36-65 years of age), 33 older adults (over 65 years of age), and 16 symptomatic patients (22-66 years of age). The TFAST is a functional test that includes 3 tasks: hand to head and back, wall wash, and gallon lift. Total repetitions were noted for each task, and the total TFAST score was calculated. Results Mean total TFAST scores were higher for young adults (107.9; 95% confidence interval [CI]: 102.5, 113.4) and middle-aged adults (105.2; 95% CI: 99.1, 111.3) as compared to the high school athletes (89.9; 95% CI: 81.2, 98.5) and older adults (74.5; 95% CI: 65.6, 83.5). All groups were significantly different (P<.05) from each other, except the young and middle-aged adults. For patients, the mean score for the symptomatic side was 100.1 (95% CI: 89.6, 110.5). The between-session reliability values for the total TFAST scores in the asymptomatic individuals were as follows: intraclass correlation coefficient (ICC) = 0.93; 95% CI: 0.60, 0.98; standard error of measurement, 6.7; and minimal detectable change based on a 95% CI, 18.5 repetitions. The ICC values for individual tasks ranged from 0.80 to 0.94 (95% CI range, 0.44-0.98). The reliability for the patient group was 0.83 (95% CI: 0.51, 0.94). Conclusion The TFAST was sensitive to detect differences in functional performance between age groups, demonstrated adequate between-session reliability, and demonstrated feasibility in a symptomatic patient group. Further assessment is needed to refine the TFAST. Development of a feasible and valid test of arm function would enhance clinical evaluation and outcome measurement. J Orthop Sports Phys Ther 2017;47(6):420-431. Epub 3 Mar 2017. doi:10.2519/jospt.2017.7136.

An upper-body rehabilitation exoskeleton Harmony with an anatomical shoulder mechanism: Design, modeling, control, and performance evaluation

We present an upper-body exoskeleton for rehabilitation, called Harmony, that provides natural coordinated motions on the shoulder with a wide range of motion, and force and impedance controllability. The exoskeleton consists of an anatomical shoulder mechanism with five active degrees of freedom, and one degree of freedom elbow and wrist mechanisms powered by series elastic actuators. The dynamic model of the exoskeleton is formulated using a recursive Newton–Euler algorithm with spatial dynamics representation. A baseline control algorithm is developed to achieve dynamic transparency and scapulohumeral rhythm assistance, and the coupled stability of the robot–human system at the baseline control is investigated. Experiments were conducted to evaluate the kinematic and dynamic characteristics of the exoskeleton. The results show that the exoskeleton exhibits good kinematic compatibility to the human body with a wide range of motion and performs task-space force and impedance control behaviors reliably.

Development and evaluation of a soft wearable weight support device for reducing muscle fatigue on shoulder

Compensating the weight of human limbs is important in reducing muscle fatigue experienced by manual laborers. In this study, a compact and lightweight soft wearable weight support device was developed and evaluated. The device supports gravitational force on the shoulder at any arm posture, although there are some limitations in its assistive performance. The device actuator consists of a cam-rod structure, a tendon-driven mechanism, and a rubber band. The desired assistive torque is translated to the shoulder joint along a tendon routing structure. Device performance was evaluated by measuring muscle activation in with-assist and without-assist conditions. Muscle activation on the deltoid was measured by surface electromyography. An experimental protocol consisting of a series of exercises was executed with six healthy subjects. The subjects raised and lowered their arm from 0 to 100 degrees for 30 times under eight conditions, which were combined with-assist and without-assist conditions, and holding the horizontal angle of the arm at 0, 30, 60, or 90 degrees against the sagittal plane. Surface electromyography data were pre-processed and analyzed using a root mean square method. When muscle fatigue occurs, the root mean square of the surface electromyography increases nonlinearly. This was calculated using the standard deviation of the root mean square. Three of six subjects showed decreased variation of the root mean square between the exercises in the with-assist condition. One subject’s result was significantly reduced (by about 57.6%) in the with-assist condition. In contrast, two subjects did not show significant difference between measurements taken in the with-assist and without-assist conditions. One subject was dropped from the experiment because the device did not fit the subject’s body. In conclusion, the effectiveness of the soft wearable weight support device in supporting shoulder movements was verified through the decreased variation of muscle activation.

Functional range of motion of the hand joints in activities of the International Classification of Functioning, Disability and Health

STUDY DESIGN

Cross-sectional research design.

INTRODUCTION

Active range of motion (AROM) is used as indicator of hand function. However, functional range of motion (FROM) data are limited, and fail to represent activities of daily living (ADL).

PURPOSE OF THE STUDY

To estimate dominant hand FROM in flexion, abduction and palmar arching in people under 50 years of age performing ADL.

METHODS

AROMs and hand postures in 24 representative ADL of the International Classification of Functioning, Disability and Health (ICF) were recorded in 12 men and 12 women. FROM data were reported by activity and ICF area, and compared with AROMs. The relationship between ROM measures to gender and hand size was analyzed by correlation.

RESULTS

FROM was 5° to 28° less than available AROM depending on the joint and movement performed.

DISCUSSION

Joints do not necessarily move through full AROM while performing ADL which has benefits in retaining function despite loss of motion. This may also suggest that ADL alone are insufficient to retain or restore full AROM.

CONCLUSIONS

Therapists should consider FROM requirements and normal AROM when defining hand therapy goals, interventions and evaluating the success of treatment.

LEVEL OF EVIDENCE

N/A.

Preliminary design and control of a soft exosuit for assisting elbow movements and hand grasping in activities of daily living

The development of a portable assistive device to aid patients affected by neuromuscular disorders has been the ultimate goal of assistive robots since the late 1960s. Despite significant advances in recent decades, traditional rigid exoskeletons are constrained by limited portability, safety, ergonomics, autonomy and, most of all, cost. In this study, we present the design and control of a soft, textile-based exosuit for assisting elbow flexion/extension and hand open/close. We describe a model-based design, characterisation and testing of two independent actuator modules for the elbow and hand, respectively. Both actuators drive a set of artificial tendons, routed through the exosuit along specific load paths, that apply torques to the human joints by means of anchor points. Key features in our design are under-actuation and the use of electromagnetic clutches to unload the motors during static posture. These two aspects, along with the use of 3D printed components and off-the-shelf fabric materials, contribute to cut down the power requirements, mass and overall cost of the system, making it a more likely candidate for daily use and enlarging its target population. Low-level control is accomplished by a computationally efficient machine learning algorithm that derives the system’s model from sensory data, ensuring high tracking accuracy despite the uncertainties deriving from its soft architecture. The resulting system is a low-profile, low-cost and wearable exosuit designed to intuitively assist the wearer in activities of daily living.

The significance of the supratrochlear aperture (STA) in elbow range of motion: an anatomical study

Assessment of the range of motion at a joint is among the methods employed by orthopedic surgeons and physiotherapists to determine courses of therapy and joint recovery. Females tend to have a greater range of motion at the elbow joint than males. In the present case-control study, the elbow extension angle was compared between males and females with and without the supratrochlear aperture. A total of 453 dry humeri and their corresponding ulnae were included in the study, and elbow extension angle was measured using a goniometer. The average extension angle in this sample was 173°, and it was significantly greater when the STA was present ([Formula: see text] = 175.4°) than when it was absent ([Formula: see text] = 171°). It was greater in females ([Formula: see text] = 174.5°) than in males ([Formula: see text] = 171.3°) irrespective of STA status, and was greater on the left in both sexes. Hyperextension characterized 13 % of the sample, whereas the majority (76 %) showed hypoextension and only a few (11 %) exhibited normal extension. Trochlear notch depth and olecranon-coronoid distance would found to be useful for predicting the presence of the supratrochlear aperture, while the transverse and vertical diameters of the supratrochlear aperture were found to be the most useful parameters when predicting the degree of extension. The functional benefits of hyperextension at the elbow joint are not fully understood. However, these results are important to orthopedic surgeons and physiotherapists as they permit a greater understanding of normal elbow range of motion in the South African population.

Single-stage Reconstruction of Elbow Flexion Associated with Massive Soft-Tissue Defect Using the Latissimus Dorsi Muscle Bipolar Rotational Transfer

In the upper extremity, the latissimus dorsi muscle can be used as an ipsilateral rotational muscle flap for soft-tissue coverage or functional reconstruction of arm and elbow. Patients who have both major soft-tissue loss and functional deficits can be successfully treated with a single-stage functional latissimus dorsi rotational muscle transfer that provides simultaneous soft-tissue coverage and functional reconstruction.

METHODS

Our data base was queried for all patients undergoing a rotational latissimus dorsi muscle transfer for simultaneous soft-tissue coverage and functional reconstruction of elbow flexion. Four patients were identified. A chart review documented the mechanism of injury, associated injuries, soft-tissue defect size, number of surgical procedures, length of follow-up, last elbow range of motion, and flexion strength.

RESULTS

Four patients with loss of elbow flexion due to traumatic loss of the anterior compartment muscles and the overlying soft tissue underwent simultaneous soft-tissue coverage and elbow flexorplasty using the ipsilateral latissimus dorsi as a bipolar muscle rotational tissue transfer. All flaps survived and had a recovery of Medical Research Council Grade 4/5 elbow flexion strength. No additional procedures were required for elbow flexion. The surgical technique is described and supplemented with surgical technique video and patient outcome.

CONCLUSIONS

This patient series augments the data provided in other series supporting the safety and efficacy of this procedure which provides both soft-tissue coverage and functional restoration of elbow flexion as a single-stage procedure in the setting of massive traumatic soft-tissue loss of the arm.