Kinematics Of Upper Extremity Research Articles

Recovery of kinematic arm function in well-performing people with subacute stroke: a longitudinal cohort study

BackgroundMost motor function improvements in people who have experienced strokes occur within the first 3 months. However, individuals showing complete or nearly complete arm function recovery, as assessed using clinical scales, still show certain movement kinematic deficits at 3 months, post-stroke. This study evaluated the changes in upper extremity kinematics, in individuals demonstrating minor clinical motor impairments, 3–12 months post-stroke, and also examined the association between kinematics and the subjects’s self-perceived hand abilities during the chronic stage, 12 months post-stroke.MethodsForty-two subjects recovering from strokes and having Fugl-Meyer upper extremity motor assessment scores ≥60 were included from the Stroke Arm Longitudinal Study at the University of Gothenburg (SALGOT). Kinematic analyses of a drinking task, performed 3, 6, and 12 months post-stroke, were compared with kinematic analyses performed in 35 healthy controls. The Stroke Impact Scale-Hand domain was evaluated at the 12-month follow-up.ResultsThere were no significant changes in kinematic performance between 3 and 12 months, post-stroke. The patients recovering from stroke showed lower peak elbow extension velocities, and increased shoulder abduction and trunk displacement during drinking than did healthy controls, at all time points. At 12 months, post-stroke, better self-perceived arm functions correlated with improved trunk displacements, movement times, movement units, and time to peak velocity percentages.ConclusionKinematic movement deficits, observed at 3 months post-stroke, remained unchanged at 12 months. Movement kinematics were associated with the patient’s self-perceived ability to use their more affected hand.Trial registrationClinicalTrials: NCT01115348.

Does local dynamic stability of kayak paddling technique affect the sports performance? A pilot study

ABSTRACTDuring competition, kayak athletes must optimally adapt to environmental factors (e.g. wind, waves) to achieve peak performance. However, the ability to adapt to such perturbations has never been assessed in kayak paddling. Therefore, the aim of the current study was to evaluate the local dynamic stability in sports technique of youth sprint kayak athletes. In a cross-sectional study, 14 healthy male athletes were recruited from an elite youth sprint kayak squad. During an incremental kayak ergometer test, mean power, heart rates and local dynamic technique stability of hands, arms, trunk and paddle were registered and the association with the athletes 2000 m free-water times were estimated using mixed models. The 2000 m free-water performance significantly predicted the paddles (p = .037) local dynamic stability whereas no association was found for the trunk or the upper extremity kinematics. In conclusion, kayak athletes with high-performance capability over 2000 m paddling depict high local dynamic technique stability. This emphasizes the importance of a stable technique for advanced kayak skills, especially regarding paddling movements.

Stroke-affected upper extremity movement assessment via continuous relative phase analysis

Paper presents the quantified assessment of stroke-affected upper extremity (UE) coordination via continuous relative phase (CRP) analysis. 14 post-stroke patients were divided into 3 groups based on the severity of impairment according to Wolf Motor Function Test (WMFT). CRP was determined based on UE kinematics parameters measured using inertial measurement units fixed on arm, forearm and hand while subjects performed designated movement. UE movement cycles were analysed based on the metrics derived from phase planes, the phase angle and CRP plots, as well as the calculated range of motions and CRP variability rates. It was found that CRP variability is associated with impairment level, i.e. it is decreasing with a higher level of dysfunction. Therefore, the CRP might serve as measurable quantity and could be valuable for supporting clinical assessment and quantifying impairment severity of UE motor functions.

Influence of Work Pace on Upper Extremity Kinematics and Muscle Activity in a Short-Cycle Repetitive Pick-and-Place Task.

This study investigated the extent to which controlled changes in work pace in a cyclic pick-and-place task influence upper extremity kinematics and muscle activity, and whether an effect depends on working height. Thirteen participants performed the task for 4 min at each of five work paces ranging from 8 to 12 cycles·min-1 in each of two experimental conditions where the hand was moved horizontally with an average upper arm elevation of 30° and 50°, respectively. For each work cycle, we calculated the average and standard deviation of the upper arm elevation angle and the activity of the trapezius and deltoid muscles, as well as the angular peak velocity. We summarized these seven variables by calculating averages across cycles and cycle-to-cycle variabilities. At 30° arm elevation, pace significantly influenced within-cycle angle variation, cycle-to-cycle variability of the average angle, angular peak velocity, and cycle-to-cycle variability of peak velocity. However, only angular peak velocity increased monotonically across all paces from 8 to 12 cycles·min-1). Average activity in the trapezius and the deltoid were the only muscle activity variables to increase consistently with pace. These effects of work pace did not change with working height. The present study did not find any consistent work pace effect on upper extremity kinematics and muscle activity, in spite of a comprehensive empirical basis compared to previous literature. While our results suggest that work pace may not be of critical concern in an occupational health context, we encourage further studies verifying or disproving this notion.

The Effect of Shoulder Plyometric Training on Amortization Time and Upper-Extremity Kinematics

Plyometric training is credited with providing benefits in performance and dynamic restraint. However, limited prospective data exist quantifying kinematic adaptations such as amortization time, glenohumeral rotation, and scapulothoracic position, which may underlie the efficacy of plyometric training for upper-extremity rehabilitation or performance enhancement. To measure upper-extremity kinematics and plyometric phase times before and after an 8-wk upper-extremity strength- and plyometric-training program. Randomized pretest-posttest design. Research laboratory. 40 recreationally active men (plyometric group, age 20.43 ± 1.40 y, height 180.00 ± 8.80 cm, weight 73.07 ± 7.21 kg; strength group, age 21.95 ± 3.40 y, height 173.98 ± 11.91 cm, weight 74.79 ± 13.55 kg). Participants were randomly assigned to either a strength-training group or a strength- and plyometric-training group. Each participant performed the assigned training for 8 wk. Dynamic and static glenohumeral and scapular-rotation measurements were taken before and after the training programs. Dynamic measurement of scapular rotation and time spent in each plyometric phase (concentric, eccentric, and amortization) during a ball-toss exercise were recorded while the subjects were fitted with an electromagnetic tracking system. Static measures included scapular upward rotation at 3 different glenohumeral-abduction angles, glenohumeral internal rotation, and glenohumeral external rotation. Posttesting showed that both groups significantly decreased the time spent in the amortization, concentric, and eccentric phases of a ball-toss exercise (P < .01). Both groups also exhibited significantly decreased static external rotation and increased dynamic scapular upward rotation after the training period (P < .01). The only difference between the training protocols was that the plyometric-training group exhibited an increase in internal rotation that was not present in the strength-training group (P < .01). These findings support the use of both upper-extremity plyometrics and strength training for reducing commonly identified upper-extremity-injury risk factors and improving upper-extremity performance.

The Impact of Fatigue on Baseball Pitching Mechanics in Adolescent Male Pitchers

To determine if shoulder and elbow kinematics, pitching velocity and accuracy, and pain change during a simulated baseball game in adolescent pitchers. Adolescent male pitchers aged 13 to 16years were included. Pitchers were excluded if they had undergone previous shoulder or elbow surgery, currently had a known shoulder or elbow injury, or were unable to complete the simulated game for any reason. Shoulder range of motion was assessed before and after the game. Velocity and accuracy were measured for every pitch, and every 15th pitch was videotaped from 2 orthogonal views in high definition at 240Hz. Quantitative and qualitative mechanics were measured from these videos. Perceived fatigue and pain were assessed after each inning using a visual analog scale. Data were statistically analyzed using a repeated-measures analysis of variance. Twenty-eight elite adolescent pitchers were included. These pitchers, on average, were aged 14.6 ± 0.9years (mean ± standard deviation), had been pitching for 6.3 ± 1.7years, and threw 94 ± 58 pitches per week. Our experimental model functioned as expected in that pitchers became progressively more fatigued (0.3 ± 0.6 to 3.5 ± 2.1), had more pain (0.1 ± 0.4 to 1.6 ± 2.2), and pitched with a lower velocity (73 ± 5 mph to 71 ± 6 mph) as pitch number increased (P < .001, P= .001, and P < .001, respectively). Knee flexion at ball release progressively increased (49° ± 15° to 53° ± 15°) with pitch number (P= .008). Hip-to-shoulder separation significantly decreased as pitch number increased, from 90% ± 40% at pitch 15 to 40% ± 50% at pitch 90 (P < .001). Upper extremity kinematics remained unchanged (P > .271 in all cases, 91% power for elbow flexion at ball release). External rotation and total range of motion in the pitching shoulder significantly increased after pitching (P= .007 and P= .047, respectively). As pitchers progress through a simulated game, they throw lower-velocity pitches, become fatigued, and have more pain. Core and leg musculature becomes fatigued before upper extremity kinematics changes. On the basis of these results, there is the potential that core strengthening and leg strengthening may be valuable adjuncts to prevent upper extremity injury. Further studies specifically looking at this must be conducted.

A Kinematic Approach to Understanding Performance in Upper-Extremity Function during a Goal-Directed Man-Machine Interface Task in a Submariner Environment.

In December of 2014, the United States Congress funded a fundamental shift in the recruiting policy of the US Navy Submarine Force to include the integration of women. As a result, design modifications became necessary, especially those that facilitate integration without inflating costs. Current cost levels associated with new submarine design(s) are maintained through the use of legacy components and systems. Additionally, many of the systems aboard are computer controlled, necessitating man-machine interfaces. As common practice, military activities that involve man-machine interfaces have always focused on the dexterity of the hands, often neglecting the role of movement in the task; therefore, there is a need to understand upper-extremity kinematics issues associated with man-machine interfaces. Joint kinematics of the right upper extremity of 10 subjects was measured using an optoelectronic motion capture system. Center of gravity displacements were measured using a force plate during touchscreen movement tasks paced by six different movement frequencies from a metronome (0, 1.0, 1.3, 1.7, 2.0, and 2.7 Hz). Results showed no significant difference in touch accuracy, task completion time, shoulder and elbow angular displacements, and shoulder and elbow flexion/extension velocity; however, a significant difference (0.002; p ≤ 0.05) in shoulder adduction/abduction velocity was observed. In arranging systems and components in submarine and surface vessel environments, consideration in not only providing a means of adjustability (e.g., height, proximity, and orientation) but in the dimensions of the systems and components themselves must also be considered based on the required operation.

Modifications in Wheelchair Propulsion Technique with Speed.

Repetitive loading of the upper limb joints during manual wheelchair (WC) propulsion (WCP) has been identified as a factor that contributes to shoulder pain, leading to loss of independence and decreased quality of life. The purpose of this study was to determine how individual manual WC users with paraplegia modify propulsion mechanics to accommodate expected increases in reaction forces (RFs) generated at the pushrim with self-selected increases in WCP speed. Upper extremity kinematics and pushrim RFs were measured for 40 experienced manual WC users with paraplegia while propelling on a stationary ergometer at self-selected free and fast propulsion speeds. Upper extremity kinematics and kinetics were compared within subject between propulsion speeds. Between group and within-subject differences were determined (α = 0.05). Increased propulsion speed was accompanied by increases in RF magnitude (22 of 40, >10 N) and shoulder net joint moment (NJM, 15 of 40, >10 Nm) and decreases in pushrim contact duration. Within-subject comparison indicated that 27% of participants modified their WCP mechanics with increases in speed by regulating RF orientation relative to the upper extremity segments. Reorientation of the RF relative to the upper extremity segments can be used as an effective strategy for mitigating rotational demands (NJM) imposed on the shoulder at increased propulsion speeds. Identification of propulsion strategies that individuals can use to effectively accommodate for increases in RFs is an important step toward preserving musculoskeletal health of the shoulder and improving health-related quality of life.

Effects of Pitching a Simulated Game on Upper Extremity Kinematics in Youth Baseball Pitchers

Effects of Pitching a Simulated Game on Upper Extremity Kinematics in Youth Baseball Pitchers

Descriptive analysis of kinematics and kinetics of catchers throwing to second base from their knees

In order to decrease the amount of time that it takes the catcher to throw the ball, a catcher may chose to throw from the knees. Upper extremity kinematics may play a significant role in the kinetics about the elbow observed in catchers throwing from the knees. If relationships between kinematics and kinetics exist then the development of training and coaching instruction may help in reduced upper extremity injury risk. Twenty-two baseball and softball catchers (14.36±3.86years; 165.11±17.54cm; 65.67±20.60kg) volunteered. The catchers exhibited a less trunk rotation (5.6±16.2°), greater elbow flexion (87.9±21.4°) and decreased humeral elevation (71.1±12.3°) at the event of maximum shoulder external rotation as compared to what has previously reported in catchers. These variables are important, as they have previously been established as potential injury risk factors in pitchers, however it is not yet clear the role these variables play in catchers’ risk of injury. A positive relationship between elbow varus torque during the deceleration phase and elbow flexion at MIR was observed (r=0.609; p=0.003). Throwing from the knees reduces a catcher’s ability to utilize the proximal kinetic chain and this may help to explain why their kinematics and kinetics differ from what has previously been presented in the literature.

Hip and upper extremity kinematics in youth baseball pitchers

The purpose of this study was to examine the relationship between dynamic hip rotational range of motion and upper extremity kinematics during baseball pitching. Thirty-one youth baseball pitchers (10.87 ± 0.92 years; 150.03 ± 5.48 cm; 44.83 ± 8.04 kg) participated. A strong correlation was found between stance hip rotation and scapular upward rotation at maximum shoulder external rotation (r = 0.531, P = 0.002) and at ball release (r = 0.536, P = 0.002). No statistically significant correlations were found between dynamic hip rotational range of motion and passive hip range of motion. Hip range of motion deficits can constrain pelvis rotation and limit energy generation in the lower extremities. Shoulder pathomechanics can then develop as greater responsibility is placed on the shoulder to generate the energy lost from the proximal segments, increasing risk of upper extremity injury. Additionally, it appears that passive seated measurements of hip range of motion may not accurately reflect the dynamic range of motion of the hips through the progression of the pitch cycle.

Coordination of Reach-to-Grasp Kinematics in Individuals With Childhood-Onset Dystonia Due to Hemiplegic Cerebral Palsy.

Functional reaching is impaired in dystonia. Here, we analyze upper extremity kinematics to quantify timing and coordination abnormalities during unimanual reach-to-grasp movements in individuals with childhood-onset unilateral wrist dystonia. Kinematics were measured during movements of both upper limbs in a patient group ( n = 11, age = 17.5 ±5 years), and a typically developing control group ( n = 9, age = 16.6 ±5 years). Hand aperture was computed to study the coordination of reach and grasp. Time-varying joint synergies within one upper limb were calculated using a novel technique based on principal component analysis to study intra-limb coordination. In the non-dominant arm, results indicate reduced coordination between reach and grasp in patients who could not lift the grasped object compared to those who could lift it. Lifters exhibit incoordination in distal upper extremity joints later in the movement and non-lifters lacked coordination throughout the movement and in the whole upper limb. The amount of atypical coordination correlates with dystonia severity in patients. Reduced coordination during movement may reflect deficits in the execution of simultaneous movements, motor planning, or muscle activation. Rehabilitation efforts can focus on particular time points when kinematic patterns deviate abnormally to improve functional reaching in individuals with childhood-onset dystonia.

The effect of breast support and breast pain on upper-extremity kinematics during running: implications for females with large breasts

The relationship between inappropriate breast support and upper-extremity kinematics for female runners is unclear. The purpose of this study was to investigate the effect of breast support and breast pain on upper-extremity kinematics during running. Eleven female recreational runners with larger breasts (UK D and E cup) completed a 7 min 20 s treadmill run (2.58 m · s−1) in a high and low breast support condition. Multi-planar breast and upper-extremity kinematic data were captured in each breast support condition by eight infrared cameras for 30 s towards the end of the run. Breast pain was rated at the end of each treadmill run using a numeric analogue scale. The high support bra reduced breast kinematics and decreased breast pain (P < 0.05). Upper-extremity kinematics did not differ between breast support conditions (P > 0.05), although some moderate positive correlations were found between thorax range of motion and breast kinematics (r = 0.54 to 0.73). Thorax and arm kinematics do not appear to be influenced by breast support level in female runners with large breasts. A high support bra that offers good multi-planar breast support is recommended for female runners with larger breasts to reduce breast pain.

Walking-Assisted Gait in Rehabilitation

Walkers are extensively used by individuals to improve stability and ambulatory ability. Despite common usage and prolonged existence, the basic walker design still remained unchanged. The objective of this study is to develop an instrumented walker and evaluate the force transferred through the subject hand's resultant pressures. The corresponding forces are used for the analyses of upper extremity kinetics and kinematics. Human motion tracking system is used for the kinematic analysis, which is used to modify a walker that is capable of reducing the stress experienced by the subject without changing the usage pattern of the walker. The upper extremity kinematics and kinetics data were acquired through QTM motion capturing system incorporate with Visual3D motion analysis system. The internal force and joint moment for the wrist, elbow and shoulder were determined using inverse dynamics method.

Upper Extremity Kinematics and Kinetics During the Performance of a Stationary Wheelie in Manual Wheelchair Users With a Spinal Cord Injury

No comprehensive biomechanical study has documented upper extremity (U/E) kinematics and kinetics during the performance of wheelchair wheelies among manual wheelchair users (MWUs). The aim of this study was to describe movement strategies (kinematics), mechanical loads (kinetics), and power at the nondominant U/E joints during a wheelie among MWUs with spinal cord injury (SCI). During a laboratory assessment, 16 MWUs with SCI completed four wheelie trials on a rigid surface. Each participant's wheelchair was equipped with instrumented wheels to record handrim kinetics, while U/E and wheelchair kinematics were recorded with a 3D motion analysis system. The greatest mean and peak total net joint moments were generated by the shoulder flexors (mean = 7.2 ± 3.5 N·m; peak = 20.7 ± 12.9 N·m) and internal rotators (mean = 3.8 ± 2.2 N·m; peak = 11.4 ± 10.9 N·m) as well as by the elbow flexors (mean = 5.5 ± 2.5 N·m; peak = 14.1 ± 7.6 N·m) during the performance of wheelies. Shoulder flexor and internal rotator efforts predominantly generate the effort needed to lift the front wheels of the wheelchair, whereas the elbow flexor muscles control these shoulder efforts to reach a state of balance. In combination with a task-specific training program that remains essential to properly learn how to control wheelies among MWUs with SCI, rehabilitation professionals should also propose a shoulder flexor, internal rotator, and elbow flexor strengthening program.

Upper extremity kinematic and kinetic adaptations during a fatiguing repetitive task

Repetitive low-force contractions are common in the workplace and yet can lead to muscle fatigue and work-related musculoskeletal disorders. The current study aimed to investigate potential motion adaptations during a simulated repetitive light assembly work task designed to fatigue the shoulder region, focusing on changes over time and age-related group differences. Ten younger and ten older participants performed four 20-min task sessions separated by short breaks. Mean and variability of joint angles and scapular elevation, joint net moments for the shoulder, elbow, and wrist were calculated from upper extremity kinematics recorded by a motion tracking system. Results showed that joint angle and joint torque decreased across sessions and across multiple joints and segments. Increased kinematic variability over time was observed in the shoulder joint; however, decreased kinematic variability over time was seen in the more distal part of the upper limb. The changes of motion adaptations were sensitive to the task-break schedule. The results suggested that kinematic and kinetic adaptations occurred to reduce the biomechanical loading on the fatigued shoulder region. In addition, the kinematic and kinetic responses at the elbow and wrist joints also changed, possibly to compensate for the increased variability caused by the shoulder joint while still maintaining task requirements. These motion strategies in responses to muscle fatigue were similar between two age groups although the older group showed more effort in adaptation than the younger in terms of magnitude and affected body parts.

Upper Extremity Kinematics in Pediatric and Young Adult Populations during Activities of Daily Living

Age-related differences in upper extremity (UE) kinematics during activities of daily living are poorly understood. To develop control databases for clinical studies, a greater understanding of UE mechanics and potential changes in motion as a function of age is needed. The purpose of this research was to examine age-related differences in threedimensional UE kinematics between young adult and pediatric groups while performing activities of daily living. Fifteen young adults (n=15) aged 18-24 years (mean age: 20.2 years) and fifteen pediatric participants (n=15) aged 7-9 years (mean age: 8.3 years) participated in the study. An eight-camera Vicon MCam system was used to record UE motion during the performance of three tasks: drinking, eating, and a simulated perineal care task. Significant differences in mean maximum joint angles were found between the age groups for all three tasks. No significant differences were found in kinematics data between the dominant and non-dominant arms for any task. Differential UE movement patterns may exist due to differences in experience with the tasks, anthropometrics, techniques used to complete the task, and/or neuromaturational levels. These results emphasize the need for age-matched control data for clinical studies of UE motion.

Upper Extremity Kinematics in Sonographers During Kidney Scanning

To understand the mechanisms involved that lead to the high prevalence of work-related musculoskeletal disorders in sonographers, this motion capture study evaluated upper extremity kinematics during kidney scans. The purpose of this study was to provide an evaluation of joint ranges of motion during scanning, which could be helpful in assessing risk of injury. A Vicon MX motion capture system recorded reflective marker positions while four sonographers scanned a volunteer’s kidneys. The results indicated that sonographers were scanning with their shoulders in flexion, abduction, and external rotation. The elbows were in flexion and the wrists in extension in all cases with the exception of portions of one scan. Shoulder abduction and wrist extension angles exceeded acceptable published limits. These results could be used to improve patient and sonographer positioning, equipment adjustability, and transducer design.

Joint Contribution to Fingertip Movement During a Number Entry Task: An Application of Jacobian Matrix

Upper extremity kinematics during keyboard use is associated with musculoskeletal health among computer users; however, specific kinematics patterns are unclear. This study aimed to determine the dynamic roles of the shoulder, elbow, wrist and metacarpophalangeal (MCP) joints during a number entry task. Six subjects typed in phone numbers using their right index finger on a stand-alone numeric keypad. The contribution of each joint of the upper extremity to the fingertip movement during the task was calculated from the joint angle trajectory and the Jacobian matrix of a nine-degree-of-freedom kinematic representation of the finger, hand, forearm and upper arm. The results indicated that in the vertical direction where the greatest fingertip movement occurred, the MCP, wrist, elbow (including forearm) and shoulder joint contributed 10.2%, 55.6%, 27.7% and 6.5%, respectively, to the downward motion of the index finger averaged across subjects. The results demonstrated that the wrist and elbow contribute the most to the fingertip vertical movement, indicating that they play a major role in the keying motion and have a dynamic load beyond maintaining posture.

A Biomechanical Comparison of Pitching From a Mound Versus Flat Ground in Adolescent Baseball Pitchers

Background:Baseball professionals believe that pitching from a mound can increase the stresses placed on the body.Hypothesis:There is no difference in kinematics or kinetics in pitching from a mound versus flat-ground conditions in adolescent baseball pitchers.Study Design:Laboratory investigation.Methods:The fastball pitching motions of 15 adolescent baseball pitchers, including upper extremity kinematics and kinetics and lead- and trail-leg kinematics, were evaluated while pitching from the mound and flat ground. Student t tests were used to determine the differences between the 2 testing conditions.Results:Maximum external glenohumeral rotation was similar between the 2 conditions (134° ± 14° mound vs 133° ± 14° flat ground, P = 0.10). Ankle plantar flexion of the lead leg at ball release was greater in the flat-ground condition (−20° ± 10° mound vs −15° ± 12° flat ground, P = 0.01). A statistically significant increase in glenohumeral internal rotation moment (33.6 ± 12.1 Nm mound vs 31.7 ± 11.6 Nm flat ground, P = 0.01) and an increase in elbow varus moment (33.3 ± 12.3 Nm mound vs 31.4 ± 11.8 Nm flat ground, P = 0.02) was measured when pitching from the mound as compared with flat ground.Conclusion:Pitching from the mound causes increased stress on the shoulder and elbow of adolescent pitchers as compared with that from flat ground.Clinical Relevance:The differences in kinematics as well as increased moments in the shoulder and elbow are helpful for pitchers and their coaches to know at the beginning of their season or as they return from injury or surgery. Pitchers in these situations should start their pitching progression on flat ground and progress to the mound.