Elbow Pronation Research Articles

Upper-limb joint kinematics analysis of accuracy dart throwing at different vertical targets between different level dart players

Darts has evolved from a traditional pub room game to a professional sport. More and more people worldwide are participating in the sport of dart throwing. In order to enhance throwing performance, it is important to understand the mechanics of precise dart throwing techniques. Therefore, the purpose of this study was to investigate the fine-tune control of joint kinematics with different vertical targets between different skill levels to understand how to increase the success rate and generate precise fine-tuning of the motor system. Eight advanced players and eight intermediate players participated in this study. A motion capture system measured the kinematic data of the arm during throwing. The results indicated a significant interaction in shoulder internal rotation velocity (p = .031) and elbow supination velocity (p = .047) between advanced and intermediate groups with the different vertical targets. When intermediate players threw darts at different vertical targets, changes in shoulder internal rotation velocity and elbow supination velocity were observed. Conversely, these phenomena were not present in the advanced group. Additionally, we found that dart accuracy or light weight throwing requires an more angle of elbow pronation and generate high angular velocity of wrist palmar flexion during the release process. Based on the findings of this study, these results could provide a reference guide for dart throwing to improve the throwing performance.

Wearable Sensors Assess the Effects of Human-Robot Collaboration in Simulated Pollination.

Pollination for indoor agriculture is hampered by environmental conditions, requiring farmers to pollinate manually. This increases the musculoskeletal illness risk of workers. A potential solution involves Human-Robot Collaboration (HRC) using wearable sensor-based human motion tracking. However, the physical and biomechanical aspects of human interaction with an advanced and intelligent collaborative robot (cobot) during pollination remain unknown. This study explores the impact of HRC on upper body joint angles during pollination tasks and plant height. HRC generally resulted in a significant reduction in joint angles with flexion decreasing by an average of 32.6 degrees (p ≤ 0.001) for both shoulders and 30.5 degrees (p ≤ 0.001) for the elbows. In addition, shoulder rotation decreased by an average of 19.1 (p ≤ 0.001) degrees. However, HRC increased the left elbow supination by 28.3 degrees (p ≤ 0.001). The positive effects of HRC were reversed when the robot was unreliable (i.e., missed its target), but this effect was not applicable for the left elbow. The effect of plant height was limited with higher plant height increasing right shoulder rotation but decreasing right elbow pronation. These findings aim to shed light on both the benefits and challenges of HRC in agriculture, providing valuable insights before deploying cobots in indoor agricultural settings.

Effects of a wearable sensor–based virtual reality game on upper-extremity function in patients with stroke

BackgroundPABLO is a virtual reality game where a motion sensor system is used. Few studies have investigated the effects of the PABLO system in stroke rehabilitation. We investigated the effects of upper-extremity virtual reality training with the PABLO system in patients with stroke. MethodsStroke patients were randomly assigned to the virtual reality (n = 19) or standard rehabilitation groups (n = 18). Total of 18 sessions were conducted twice per week. The primary outcome measure was the Fugl–Meyer Assessment-Upper Extremity subscale. Secondary outcome measures included the active ranges of motion of the shoulder and elbow, the box and block test, hand grip strength, and the Stroke Impact Scale. Enjoyment of activities and side effects were also recorded. FindingsNo difference was observed between two groups in primary outcome. Virtual reality group exhibited greater improvements in the hand dexterity between groups (p = .05). In active motion, virtual reality group showed greater improvement in shoulder flexion between groups (p = .03). Virtual reality group also showed greater improvements in elbow pronation between groups (p = .03). The groups differed in their assessments of how enjoyment the rehabilitation activities were found (p = .01). No significant differences between groups were observed in any other tests. InterpretationInterventions based on the PABLO virtual reality system improved upper extremity hand function, shoulder and elbow movements, and elicited a higher degree of enjoyment from study participants, than did traditional treatment.Trials registration: The study protocol was registered at ClinicalTrials.gov PRS (No.NCT04296032).

Fractures of the Proximal Ulna: A Spectrum of Injuries and Outcomes.

The purpose of this study is to assess the effect of radial head/ neck injury in association with proximal ulna fractures. Between 2006 and 2020, 107 patients presented to our academic medical center for treatment of a proximal ulna fracture and were enrolled into an IRB-approved database. Radiographs, injury details, and surgical interventions were retrospectively reviewed. Patients were classified as having an isolated proximal ulna fracture (PU), a PU fracture with an associated radial head dislocation (M-D), or a Monteggia fracture with an associated radial head fracture (M-V). Clinical and functional outcomes were assessed at follow-up to determine what differences exist between fracture patterns. Statistics were generated using Chi-squared tests for categorical variables and one-way ANOVA tests for numerical variables. While all patients ultimately healed, time to radiographic healing in the PU cohort was shorter at 3.57 ± 1.7months when compared to the M-V cohort (5.67 ± 3.8months) (p < 0.05). At follow-up, patients in the M-V cohort had poorer elbow pronation and supination when compared to the PU and M-D cohorts (p < 0.05). Patients within the PU cohort had fewer complications than those in the M-D and M-V cohorts (p < 0.05). No differences were found between the three cohorts in regard to rates of reoperation, non-union, wound infection, and nerve compression (p > 0.05). The Monteggia fracture with a concomitant radial head/neck fracture is a more disabling injury pattern when compared to an isolated proximal ulna fracture and Monteggia fracture without an associated radial head/neck fracture.

Predicting the Clean Movement Technique in Crossfit® Athletes Using an Optimal Upper-Limb Range of Motion: A Prospective Cohort Study.

Background: The aim of this study was to determine the optimal upper-limb range of motion (ROM) profile for the catch phase of the clean movement (CPCM) and to identify the key ROMs for performing the CPCM in CrossFit® athletes. Methods: A prospective cohort study of twenty CrossFit® athletes aged 20–36 years was conducted. Data were collected regarding age, anthropometrics, CrossFit® training experience and upper-limb ROM. The ROM was measured using the ROM-SPORT method. After 7 months, athletes performed a clean movement with a load of 80% one repetition maximum. A Bayesian Student’s t-analysis, binary logistic regression analysis and Receiver Operating Characteristic analysis were performed. Results: The optimal upper-limb ROM profile that predicted correct CPCM performance was 78° in shoulder extension, 173° in shoulder flexion, 107° in shoulder external rotation, 89° in shoulder internal rotation, 153° in elbow flexion, 99° in elbow pronation and 92° in wrist extension (area under the curve ≥ 651; positive predictive value ≥ 80%). Shoulder external rotation, elbow pronation and wrist extension were found to be the most important ROMs for the efficient and safe performance of CPCM (area under the curve ≥ 854; positive predictive value ≥ 85.7%). Conclusion: The upper-limb ROM profile is associated with proper clean performance. Further studies are warranted to determine whether improving flexibility on upper-limb ROM may improve proper clean movement performance.

A new attempt to treat coronal plane fractures of the elbow joint with salvage via an anterior approach

BackgroundExisting approaches for treating elbow fractures include lateral, medial, anterior and posterior approaches, though the anterior approach is often not chosen by surgeons to avoid damage to important nerves and blood vessels. However, the anterior approach has unique advantages. The purpose of this study was to report outcomes of 38 patients with coronal plane elbow fractures treated through the anterior approach.MethodsWe retrospectively analyzed 38 cases of coronal plane elbow fracture treated through an anterior approach at our institution between March 2015 and July 2019. The length of the surgical incision, operation time, and postoperative complications were recorded. The range of flexion, extension, and rotation of the affected elbow and the healthy elbow were collected at follow-up. Functional outcomes were evaluated using the Mayo Elbow Function Score (MEPS).ResultsAll 38 patients were followed up for a mean of 21.26 months (range 12–36 months). Intraoperatively, the mean surgical incision length was 8 ± 2 cm and the mean operative time was 123 ± 59 min. At the final follow-up, solid osseous union was confirmed for all coronal plane elbow fractures. The mean elbow flexion arc was 129 ± 7°, and the extension arc was 9 ± 6°. The mean pronation arc was 83 ± 3°, and the supination arc was 80 ± 3°. The mean MEPS was 90 ± 8 points, with 18 excellent cases and 20 cases of excellent and good results, respectively. In 31 cases, there was no significant difference in elbow extension, flexion, or pronation between the single-fracture and healthy elbows (P > 0.05), though the arc of supination was slightly worse than that of the healthy elbow (P < 0.05). VAS pain scores before the operation, at three months after the operation, and during follow-up were compared, and pain was significantly reduced after treatment (P < 0.05). Two patients experienced transient postoperative median nerve paralysis, from which they recovered within three months. One patient had mild heterotopic ossification and was not treated because it did not affect the function of the elbow joint. All patients returned to work and were satisfied with the treatment.ConclusionThe anterior approach has the benefits of simplicity, safety, minimal invasiveness, excellent exposure, and satisfactory prognosis for coronal plane elbow fracture.

The impact of an underactuated arm exoskeleton on wrist and elbow kinematics during Prioritized Activities of daily living

This study addresses the feasibility of underactuated arm exoskeletons as an alternative solution to the often bulky and heavy exoskeletons which actuate the shoulder with 3 DoF. Specifically, the study investigates how the wrist and elbow joint adapts their kinematics when the shoulder abduction is constrained. Ten healthy participants conducted three different grasping activities of daily living, during natural motion and during constrained shoulder abduction at two fixed angles: the resting position angle and at an angle of 10 ° abduction from the resting position. Motion capture data was collected and used as input for a musculoskeletal computer model adapted to this study. Statistical parametric mapping tools were employed to analyze the joint angles estimated by the model. The results show significant differences within the joint angles when the shoulder abduction is constrained. The wrist flexion angle deviated up to 13.6 ° and the elbow pronation angle decreased by 8.7 ° on average throughout the movement compared to the natural motion during restricted shoulder abduction motion. Thus, the shoulder could be underactuated and the participants could still accomplish the activities of daily living with changes in the wrist and elbow joint kinematic angles.

Investigating the Effect of Keyboard Distance on the Posture and 3D Moments of Wrist and Elbow Joints among Males Using OpenSim.

Musculoskeletal disorders (MSDs) of the upper extremities and computer use are common in modern societies, and both show a growing trend. This study was conducted to determine the posture and 3D moments of wrist and elbow joints at different keyboard distances on a desk. Twelve healthy right-handed male volunteers attended the motion analysis laboratory. A keyboard was placed at three different distances from the participants' bodies while performing a standard computer task. The workstation was adjusted according to ANSI/HFES-100-2007 standard for each participant to maintain a comfortable ergonomic posture for controlling confounding variables. Qualisys motion capture system, OpenSim (Ver. 4.1), and visual analog scale were used to collect and analyze the data. The highest levels of wrist flexion and radial deviation as well as elbow flexion and pronation were observed when the keyboard was at the edge of the desk. When the keyboard was 8 cm away from the edge of the desk, the right wrist flexion and radial deviation decreased 83% and 89%, respectively. In the left wrist, flexion and radial deviation decreased 94%. With increasing the distance of the keyboard from the edge of the desk, the right elbow flexion, pronation, and left elbow flexion decreased, 95%, 76%, and 85%, respectively. No significant difference was found for the left elbow pronation, wrist, and elbow joint moments, in the studied keyboard distances. However, a cut-off point has to be specified because large keyboard distances cause high extension and flexion of the limbs. The keyboard position relative to the body is an important parameter in computer work and has a significant impact on the posture of the upper extremities. A keyboard should be located at a distance that allows the upper extremities to remain in a neutral position so that the risk of MSDs is reduced.

Kinematics and workspace analysis of a robotic device for performing rehabilitation therapy of upper limb in stroke-affected patients

Exoskeleton robots generally have multi-functions and one such function is doing rehabilitation therapy in upper limb and lower limb in stroke-affected patients. A novel hybrid (serial-parallel) robot manipulator was proposed in this paper for rehabilitation of upper limb and its kinematics are studied systematically. This robot manipulator intends to perform wrist flexion, wrist extension, wrist radial deviation, wrist ulnar deviation, elbow flexion, elbow extension, elbow pronation and elbow supination motions. The contemporary mechanical designs especially the kinematic structure of upper limb exoskeleton robots have a unique feature that is, almost all of them use serial manipulators, and few others used parallel manipulators. The kinematic structure of the proposed robot is that of a hybrid manipulator (two parallel manipulators connected in series) which has 4-degrees-of-freedom. It is composed of an upper 3SPS-type parallel manipulator and 2SPR-type parallel manipulator connected in series. The Jacobian and Hessian Matrix method was used to derive the manipulator kinematic formula for solving the displacement, velocity and acceleration. A 3D model of the robotic arm was constructed and analyzed by simulation. The positioning workspace of manipulator was constructed and analyzed. The 3SPS-type parallel manipulator has good kinematic characteristics while performing wrist motions. The 2SPR-type parallel manipulator produced singular configuration, while performing the desired rehabilitation elbow motions, it was found to not be suitable for usage in performing rehabilitation therapy in stroke-affected patients.

Stride-Phase Kinematic Parameters That Predict Peak Elbow Varus Torque.

Background:During baseball pitching, a high amount of elbow varus torque in the arm cocking-to-acceleration phase is thought to be a biomechanical risk factor for medial elbow pain and injury. The biomechanics of the stride phase may provide preparation for the arm cocking-to-acceleration phase that follows it.Purpose:To determine the kinematic parameters that predict peak elbow varus torque during the stride phase of pitching.Study Design:Descriptive laboratory study.Methods:Participants were 107 high school baseball pitchers (age range, 15-18 years) without shoulder or elbow problems. Whole-body kinematics and kinetics during fastball pitching were analyzed using 3-dimensional measurements from 36 retroreflective markers. A total of 26 kinematic parameters of the upper and lower limbs during the stride phase leading up to the stride foot contact were extracted for multiple regression analysis to assess their combined effect on the magnitude of peak elbow varus torque.Results:Increased wrist extension, elbow pronation, knee flexion on the leading leg, knee extension on the trailing leg at stride foot contact, and upward displacement of the body’s center of mass in the stride phase were significantly correlated with decreased peak elbow varus torque (all P < .05). Moreover, 38% of the variance in peak elbow varus torque was explained by a combination of these 5 significant kinematic variables (P < .001).Conclusion:We found that 5 kinematic parameters during the stride phase and the combination of these parameters were associated with peak elbow varus torque. The stride phase provides biomechanical preparation for pitching and plays a key role in peak elbow varus torque in subsequent pitching phases.Clinical Relevance:The present data can be used to screen pitching mechanics with motion capture assessment to reduce peak elbow varus torque. Decreased peak elbow varus torque is expected to reduce the risk of elbow medial pain and injury.

Development of Adapted Guitar to Improve Motor Function After Stroke: Feasibility Study in Young Adults.

Recent research indicates that music-supported therapies may offer unique benefits for rehabilitation of motor function after stroke. We designed an adapted guitar and training task aimed to improve coordination between rhythmic and discrete movements because individuals recovering from stroke have greater difficulty performing discrete vs. rhythmic movements. In this paper, we report a feasibility study on training to play this adapted guitar in healthy young adults. Subjects (N = 10) practiced two rhythmic strumming patterns over three consecutive days using their non-dominant hand guided by an audiovisual metronome (60 bpm). They were also instructed to press a foot pedal while maintaining the strumming movement. Elbow and wrist kinematics were estimated using wireless inertial measurement units. Results showed positive mean asynchrony between strum onsets and metronome onsets, and a decrease in the standard deviation of mean asynchrony over practice. In early practice, participants slowed the strumming movement when they pressed the foot pedal, but this interference decreased on days two and three. Smoothness of the elbow movement during the strum phase, which includes the contact with the strings, increased over practice, while smoothness of the return phase did not change over practice. The predominant joint coordination pattern used for the strum phase consisted of elbow extension coupled with elbow pronation, wrist extension, and ulnar deviation. We discuss how these results fit into current music-based rehabilitation literature and outline directions for future applications of this music-supported intervention.

Assessment of elbow functional outcome after closed reduction and percutaneous pinning of displaced supracondylar humerus fractures in children

Background: The aim of the current study was to establish the functional outcome of Gartland grade III extension-type supracondylar fractures at 24 weeks after closed reduction and percutaneous pinning (CRPP) without physiotherapy. The objectives of this study were 1) to measure the elbow range of motion (ROM) at three, six, 12 and 24 weeks after CRPP for grade III supracondylar fractures; 2) to assess the functional outcome of the injured limb using the Paediatric Outcome Data Collection Instrument (PODCI) score; 3) to compare elbow functional outcome of children less than 7 years old versus children more than 7 years old and 4) to assess other risk factors or complications associated with poor outcomes after CRPP (including age and associated soft tissue injury). Patients and methods: A prospective cohort study was performed. The study included 38 children under the age of 14 years with grade III extension-type supracondylar fractures who had manipulation under anaesthesia (MUA) and crossed K-wire fixation. ROM of the affected elbow (flexion, extension, pronation and supination) was measured at three, six, 12 and 24 weeks after CRPP by the same author (AR) at each visit. The unaffected elbow was used as a control. The PODCI was also recorded. No physiotherapy was prescribed. Results: Thirty-eight children were included in the study. All components of elbow ROM improved at 24 weeks (p<0.001). At 12 but not 24 weeks, the mean elbow extension was reduced in comparison with the controls (p=0.009). Patients less than 7 years of age recovered extension more rapidly (p=0.001). Seventy-six per cent of the children achieved satisfactory PODCI results at the 24-week final follow-up. Nerve palsy (18.4%) and severe soft tissue injuries (7.9%) were the main contributory factors to a poor outcome on the PODCI assessment. Conclusion: The majority of children with displaced supracondylar fractures recover full ROM after CRPP by 24 weeks without physiotherapy. Older children, or those with associated neurovascular and soft tissue injuries had poor functional outcomes. Further studies are needed to assess if these patients will benefit from physiotherapy. Level of evidence: Level 4

Effect of assistive devices on hand and arm posture during activities of daily living

Assistive devices (ADs) are products designed to overcome the grip strength and mobility difficulties produced by ageing and different pathologies. Nevertheless, little is known about the postural effect of such devices. This work aims to quantify this effect on the entire upper limb. Ten healthy right-handed subjects performed 13 activities of daily living (ADL) with normal products and 22 ADs and both arm (shoulder, elbow and wrist) and hand (grasp types and contacts) postures were analysed. ADs were found to affect upper limb postures in ADL, reducing the use of precision grasps in the right hand by 31.9% and increasing palm contact by 26% and 29.1% in right and left hands, respectively. Nevertheless, they were also found to increase shoulder flexion, elbow pronation and wrist deviation, which may be a drawback in some pathologies. Results may help in the selection of a suitable AD for enhancing ADL performance depending on the patient's limitations due to a particular pathology.

Negative Influence of Motor Impairments on Upper Limb Movement Patterns in Children with Unilateral Cerebral Palsy. A Statistical Parametric Mapping Study.

Upper limb three-dimensional movement analysis (UL-3DMA) offers a reliable and valid tool to evaluate movement patterns in children with unilateral cerebral palsy (uCP). However, it remains unknown to what extent the underlying motor impairments explain deviant movement patterns. Such understanding is key to develop efficient rehabilitation programs. Although UL-3DMA has been shown to be a useful tool to assess movement patterns, it results in a multitude of data, challenging the clinical interpretation and consequently its implementation. UL-3DMA reports are often reduced to summary metrics, such as average or peak values per joint. However, these metrics do not take into account the continuous nature of the data or the interdependency between UL joints, and do not provide phase-specific information of the movement pattern. Moreover, summary metrics may not be sensitive enough to estimate the impact of motor impairments. Recently, Statistical Parametric Mapping (SPM) was proposed to overcome these problems. We collected UL-3DMA of 60 children with uCP and 60 typically developing children during eight functional tasks and evaluated the impact of spasticity and muscle weakness on UL movement patterns. SPM vector field analysis was used to analyze movement patterns at the level of five joints (wrist, elbow, shoulder, scapula, and trunk). Children with uCP showed deviant movement patterns in all joints during a large percentage of the movement cycle. Spasticity and muscle weakness negatively impacted on UL movement patterns during all tasks, which resulted in increased wrist flexion, elbow pronation and flexion, increased shoulder external rotation, decreased shoulder elevation with a preference for movement in the frontal plane and increased trunk internal rotation. Scapular position was altered during movement initiation, although scapular movements were not affected by muscle weakness or spasticity. In conclusion, we identified pathological movement patterns in children with uCP and additionally mapped the negative impact of spasticity and muscle weakness on these movement patterns, providing useful insights that will contribute to treatment planning. Last, we also identified a subset of the most relevant tasks for studying UL movements in children with uCP, which will facilitate the interpretation of UL-3DMA data and undoubtedly contribute to its clinical implementation.

Treatment of humeral capitellum fracture using lateral anatomic plate for distal humerus

Objective To evaluate the surgical treatment of capitellum fractures of Dubberley types ⅡB and ⅢB using lateral anatomic plate for distal humerus. Methods From October 2010 to October 2014, 11 capitellum fractures of Dubberley types ⅡB and ⅢB were treated with open reduction and internal fixation with lateral anatomic plate for distal humerus (with support). They were 7 males and 4 females, with a mean age of 33.1 years (from 24 to 71 years). Seven cases were type ⅡB and 4 type ⅢB. Reduction, fracture union, and complications were documented. The elbow function was assessed by the Mayo elbow performance score (MEPS) at the last follow-up. Results All the 11 patients were followed up for 12 to 35 months (mean, 16.1 months). All fractures united after an average time of 3.2 months (from 2.5 to 5.0 months). No avascular necrosis of the capitellum or reduction loss occurred. Traumatic arthritis was observed on the X-ray film of one case and heterotopic ossification in another. At the final follow-up, the mean elbow flexion was 121.2° (from 91.3° to 142.2°); the mean elbow extension was 7.3° (from 4.5° to 13.7°); the mean elbow pronation was 81.4° (from 53.5° to 91.2°); the mean elbow supination was 79.8° (from 65.3° to 84.7°); the mean elbow MEPS was 89.8. Eight cases were rated as excellent, 2 as good and one as fair. Conclusion As it allows reduction under direct visualization, use of lateral anatomic plate for distal humerus (with support) for capitellum fractures of Dubberley types ⅡB and ⅢB can obviously improve fixation stability of the fracture which facilitates early functional recovery of the elbow. Key words: Humeral fractures; Elbow joint; Fracture fixation, internal; Bone plates

野球の打撃動作における打撃条件の違いが上肢のキネマティクスに及ぼす影響：ティーおよび飛来球打撃条件による比較

The purpose of this study was to compare the kinematic characteristics of the upper body between baseball tee batting and pitched ball batting in order to gain basic knowledge for improvement of batting skill. Ten male collegiate baseball players (age: 20.7±1.1 yr; height: 1.75±0.05 m; body mass: 76.3±7.1 kg; athletic career: 12.7±2.7 yr) participated. They performed 2 kinds of batting: tee batting (TB) and machine-pitch batting (MB) using a pitching machine (approximate ball speed 33.3 m/s), which were set at middle ball height for the strike zone. Three-dimensional coordinate data were acquired with a motion capture system. Kinematic variables such as maximum bat-head speed, swing time, bat angle, joint angles of the upper limbs, and segment angle of the upper trunk were calculated. Differences between TB and MB were analyzed statistically using paired t-test (p<0.05). The maximum bat-head speed was significantly greater in TB than in MB, but swing times divided into 2 phases showed no significant differences between MB and TB. In the first half of the swing, the bat inclination angle was significantly larger in MB than in TB. The joint angles of the barrel-side shoulder abduction, knob-side shoulder adduction and internal rotation were significantly larger in MB than in TB, and those of the barrel-side shoulder internal rotation and individual elbow pronations were significantly larger in TB than in MB. The clockwise rotational angle of the upper trunk was significantly larger in TB than in MB. In the last half of the swing, the joint angles of the barrel-side shoulder abduction, knob-side shoulder flexion and adduction were significantly larger in MB than in TB, and that of the knob-side elbow pronation was significantly larger in TB than in MB. The changes in upper body movement in MB affected the radius of rotation of the bat about the vertical axis to control the bat easily. The movements in the last half of the swing largely resulted from those in the first half of the swing, and did not contribute to timing adjustment. These results indicate that the initial configuration of the bat and upper limbs, and movements at the beginning of the bat swing contribute to the timing adjustment of the bat for a pitched ball. The results of the present study suggest that it could be useful to pay attention to the movement of the bat and upper body in the first half of the swing as TB practice in order to improve timing adjustment.

Outcomes of Botulinum Toxin Type A Injection Followed by Rehabilitation in Cases of Cerebral Palsy With Upper Extremity Involvement.

We evaluated the efficiency of botulinum toxin type A injection followed by a rehabilitation program including individual therapy, group therapy, and occupational therapy in cases of cerebral palsy with upper extremity involvement. A total of 29 injections were performed on 25 patients, and the patients were placed on rehabilitation program. At 3-month and 6-month assessments, there was a significant improvement in lateral grip strength, 9 Hole Peg test, Upper Limb Physician's Rating Scale and pediatric functional independence measure total scores. There were significant decreases in active range of motion in elbow extension, supination, and wrist extension, and Modified Ashworth Scale in elbow flexion, elbow pronation, and wrist flexion at 6-week, 3-month, and 6-month assessments. Combination of group therapy with traditional therapy methods after injection is effective in cases of cerebral palsy with upper extremity involvement.

Upper limb joint angle measurement in occupational health

Usual human motion capture systems are designed to work in controlled laboratory conditions. For occupational health, instruments that can measure during normal daily life are essential, as the evaluation of the workers' movements is a key factor to reduce employee injury- and illness-related costs. In this paper, we present a method for joint angle measurement, combining inertial sensors (accelerometers and gyroscopes) and magnetic sensors. This method estimates wrist flexion, wrist lateral deviation, elbow flexion, elbow pronation, shoulder flexion, shoulder abduction and shoulder internal rotation. The algorithms avoid numerical integration of the signals, which allows for long-time estimations without angle estimation drift. The system has been tested both under laboratory and field conditions. Controlled laboratory tests show mean estimation errors between 0.06° and of 1.05°, and standard deviation between 2.18° and 9.20°. Field tests seem to confirm these results when no ferromagnetic materials are close to the measurement system.

Effects of the racket polar moment of inertia on dominant upper limb joint moments during tennis serve.

This study examined the effect of the polar moment of inertia of a tennis racket on upper limb loading in the serve. Eight amateur competition tennis players performed two sets of 10 serves using two rackets identical in mass, position of center of mass and moments of inertia other than the polar moment of inertia (0.00152 vs 0.00197 kg.m2). An eight-camera motion analysis system collected the 3D trajectories of 16 markers, located on the thorax, upper limbs and racket, from which shoulder, elbow and wrist net joint moments and powers were computed using inverse dynamics. During the cocking phase, increased racket polar moment of inertia was associated with significant increases in the peak shoulder extension and abduction moments, as well the peak elbow extension, valgus and supination moments. During the forward swing phase, peak wrist extension and radial deviation moments significantly increased with polar moment of inertia. During the follow-through phase, the peak shoulder adduction, elbow pronation and wrist external rotation moments displayed a significant inverse relationship with polar moment of inertia. During the forward swing, the magnitudes of negative joint power at the elbow and wrist were significantly larger when players served using the racket with a higher polar moment of inertia. Although a larger polar of inertia allows players to better tolerate off-center impacts, it also appears to place additional loads on the upper extremity when serving and may therefore increase injury risk in tennis players.

Kinematic analysis of upper extremity movement during drinking in hemiplegic subjects

BackgroundIt is necessary to analyze the kinematic properties of a paralyzed extremity to quantitatively determine the degree of impairment of hemiplegic people during functional activities of daily living (ADL) such as a drinking task. This study aimed to identify the kinematic differences between 16 hemiplegic and 32 able-bodied participants in relation to the task phases when drinking with a cup and the kinematic strategy used during motion with respect to the gravity direction. MethodsThe subjects performed a drinking task that was divided into five phases according to Murphy's phase definition: reaching, forward transport, drinking, backward transport, and returning. We found that the groups differed in terms of the movement times and the joint angles and angular velocities of the shoulder, elbow, and wrist joints. FindingsCompared to the control group, the hemiplegic participants had a larger shoulder abduction angle of at most 17.1° during all the phases, a larger shoulder flexion angle of 7.6° during the reaching phase, and a smaller shoulder flexion angle of 6.4° during the backward transporting phase. Because of these shoulder joint patterns, a smaller elbow pronation peak angle of at most 13.1° and a larger wrist extension peak angle of 12.0° were found in the motions of the hemiplegic participants, as compensation to complete the drinking task. The movement in the gravity direction during the backward transporting phase resulted in a 15.9% larger peak angular velocity for elbow extension in the hemiplegic participants compared to that of the control group. InterpretationThese quantitative kinematic patterns help provide an understanding of the movements of an affected extremity and can be useful in designing rehabilitation robots to assist hemiplegic people with ADL.