Activity Of Upper Limb Muscles Research Articles

Activation of upper limb muscles in subjects with scapular dyskinesis during bench-press and dumbbell fly on stable and unstable surfaces

Scapular dyskinesis has been associated with shoulder dysfunctions, and changes in electromyographic (EMG) activity have been reported during the execution of some exercises. To compare upper limb muscles EMG of asymptomatic subjects with and without scapular dyskinesis during bench-press and dumbbell fly exercise performed on different surface stability conditions. Twenty-eight physically active men were allocated into two groups: Control group (n= 14) and Dyskinesis group (n= 14). The participants performed six repetitions lasting three seconds of the bench press and dumbbell fly exercises with 50% of one-repetition maximum (1RM) on a bench and a Swiss ball. The EMG activity of the pectoralis major, serratus anterior, upper and lower trapezius, anterior deltoid, biceps and triceps muscles were recorded. No differences were found between groups, regardless of exercise or surface type. Inserting the unstable surface in the supine exercise promoted a slight increase in upper trapezius EMG activity for the control [4.32 (95% CI: 1.04 to 7.60)] and dyskinesis [3.30 (95% CI: 0.34 to 6.27)] groups. There is no difference in upper limb muscle EMG activity between subjects with and without scapular dyskinesis. In addition, inserting unstable surfaces did not modify EMG activity.

Effect of Physical Therapy on Muscle Synergy Structure During Standing-Up Motion of Hemiplegic Patients

Stroke patients suffer from declined physical ability, and it is important to analyze rehabilitation intervention and clarify its effect on the motion of patients. In this study, the effect of intervention on the standing-up motion of stroke patients is investigated. First, the intervention timing of a physical therapist (PT) is analyzed quantitatively from the muscle activity of upper limbs during therapy. Next, the intervention effect is evaluated based on body kinematics and muscle synergy. In this study, twenty trials are conducted, in which the standing-up motion of hemiplegic patients (n=12) is measured with and without the intervention by a PT. The results show that PTs teach hemiplegic patients the timing of lifting their buttocks during standing-up motion. Furthermore, it has been found that this intervention could improve the standing-up motion, although stroke patients had inadequate muscle synergy structure. In particular, some patients had delayed activation of the synergy and they could only stood up after they moved their center of mass toward their feet. However, the intervention by PTs could induce earlier activation of the synergy. Moreover, the intervention could properly shorten the activation duration of muscle synergy for those who had unusually inappropriate longer activation of synergy. These results imply that disordered and inadequate muscle synergy structure can be improved by proper intervention, and this study contributes to the further development of new rehabilitation methodologies.

Active Braking of Whole-Arm Reaching Movements Provides Single-Trial Neuromuscular Measures of Movement Cancellation.

Movement inhibition is an aspect of executive control that can be studied using the countermanding paradigm, wherein subjects try to cancel an impending movement following presentation of a stop signal. This paradigm permits estimation of the stop-signal reaction time or the time needed to respond to the stop signal. Numerous countermanding studies have examined fast, ballistic movements, such as saccades, even though many movements in daily life are not ballistic and can be stopped at any point during their trajectory. A benefit of studying the control of nonballistic movements is that antagonist muscle recruitment, which serves to actively brake a movement, presumably arises in response to the stop signal. Here, nine human participants (2 female) performed a center-out whole-arm reaching task with a countermanding component, while we recorded the activity of upper-limb muscles contributing to movement generation and braking. The data show a clear response on antagonist muscles to a stop signal, even for movements that have barely begun. As predicted, the timing of such antagonist recruitment relative to the stop signal covaried with conventional estimates of the stop-signal reaction time, both within and across subjects. The timing of antagonist muscle recruitment also attested to a rapid reprioritization of movement inhibition, with antagonist latencies decreasing across sequences consisting of repeated stop trials; such reprioritization also scaled with error magnitude. We conclude that antagonist muscle recruitment arises as a manifestation of a stopping process, providing a novel, accessible, and within-trial measure of the stop-signal reaction time.SIGNIFICANCE STATEMENT The countermanding or stop-signal paradigm permits estimation of how quickly subjects cancel an impending movement. Traditionally, this paradigm has been studied using simple movements, such as saccadic eye movements or button presses. Here, by measuring upper limb muscle activity while human subjects countermand whole-arm reaching movements, we show that movement cancellation often involves prominent recruitment of antagonist muscles that serves to actively brake the movement, even on movements that have barely begun. The timing of antagonist muscle recruitment correlates with traditional estimates of movement cancellation. Because they can be detected on a single-trial basis, muscle-based measures may provide a new way of characterizing movement cancellation at an unprecedented within-trial resolution.

Upper limb muscle activation during sports video gaming of persons with spinal cord injury

Objective Video gaming as a therapeutic tool has largely been studied within the stroke population with some benefits reported in upper limb motor performance, balance, coordination, and cardiovascular status. To date, muscle activation of upper limb muscles in persons with spinal cord injuries (SCI) has not been studied during video game play. In this paper, we provide descriptive and comparative data for muscle activation and strength during gaming for players with tetraplegia and paraplegia, as well as, compare these results with data from traditional arm exercises (ie, biceps curl and shoulder press) with light weights which are commonly prescribed for a home program. Participants Fourteen individuals with chronic SCI (9 tetraplegia, 5 paraplegia). Design We measured upper limb muscle activation with surface electromyography (EMG) during Wii Sports video game play. Muscle activation was recorded from the playing arm during 4 selected games and normalized to a maximum voluntary contraction (MVC). Outcome measures Heart rate and upper limb motion were recorded simultaneously with EMG. Wilcoxon signed rank tests were used to analyze differences in muscle activation between participants with paraplegia versus tetraplegia and compare gaming with traditional arm exercises with light weights. A Friedman 2-way analysis of variance identified key muscle groups active during game play. Results Overall muscle activation across the games was not different between those with paraplegia and tetraplegia. Heart rate during video game play for tennis and boxing were on average 10 to 20 beats/minute above resting heart rate. The magnitude of EMG was relatively greater for traditional arm exercises with light weights compared with game play. Conclusion The selected Wii games were able to elicit upper extremity muscle activation and elevated heart rates for individuals with SCI that may be used to target therapeutic outcomes.

노르딕워킹 운동 시 폴유형에 따른 근활성도의 변화

The changes of EMG activities on the upper and lower limb muscles with different poles(nordic pole & walking pole) during nordic walking exercise. The purpose of the study was to investigate muscle activity on the upper and lower limbs muscles with different pole during nordic walking. Within the last six months that affect gait, such as a fracture or joint surgery inexperienced college women who is physically healthy (19 students; age: 21.4±1.2 years, height: 163±4.6 cm, weight: 52±3.8 kg) were enrolled in this study and all subjects agreed to evaluate walking by using pole. Surface electromyography systems (BTS FREEEMG 300, Italy) were attached to Tibialis anterior (TA), Gastrocnemus medialis (GM), Rectus femoris (RF), Biceps femoris caput longus (BF), Biceps brachii caput longus (BB), Triceps brachii caput longus (TB), Flexor caput radialis (FCR), Extensor digitorum (ED), and integrated electromyography (IEMG) were measured. The result showed that the NW did influence the IEMG. The was no significant difference in the EMG activity on the lower limb muscles according to the pole type during Nordic walking exercise. In muscles activity of upper limb muscles was the nordic pole significantly higher than the walking poles. Nordic walking is an effective nordic walking exercise that increases safety and efficiency.

Children With and Without Dystonia Share Common Muscle Synergies While Performing Writing Tasks.

Childhood dystonia is a movement disorder characterized by muscle overflow and variability. This is the first study that investigates upper limb muscle synergies in childhood dystonia with the twofold aim of deepening the understanding of neuromotor dysfunctions and paving the way to possible synergy-based myocontrol interfaces suitable for this neurological population. Nonnegative matrix factorization was applied to the activity of upper-limb muscles recorded during the execution of writing tasks in children with dystonia and age-matched controls. Despite children with dystonia presented compromised kinematics of the writing outcome, a strikingly similarity emerged in the number and structure of the synergy vectors extracted from children in the two groups. The analysis also revealed that the timing of activation of the synergy coefficients did not significantly differ, while the amplitude of the peaks presented a slight reduction. These results suggest that the synergy analysis has the ability of capturing the uncorrupted part of the electromyographic signal in dystonia. Such an ability supports a possible future use of muscle synergies in the design of myocontrol interfaces for children with dystonia.

Short-latency muscle response patterns to multi-directional, unpredictable perturbations to balance applied to the arm are context dependent

A number of studies have shown that sensory inputs from the hand can have a profound effect in stabilizing upright posture. This suggests that the central nervous system can extract information about body motion and external forces acting on the body from cutaneous sensory signals. We have recently shown that the central nervous system determines the direction of an unpredictable force applied to the hand so rapidly that it is able to activate ankle muscles in advance of the perturbing effect that this force has at the ankles. In this study we investigate whether this rapid change in activation of lower limb muscles is an invariant response determined by the pattern of somatosensory information arising from sensory receptors in the hand or whether it adapts to changes in postural stability. We manipulated lateral stability of upright stance by changing stance width which had no effect on the activation of upper limb muscles or hand kinematics, but produced profound changes in the activation patterns of lower limb muscles when perturbations were in the medial/lateral direction without affecting the activation patterns of muscles when perturbations were in the anterior/posterior direction.

The influence of axle position and the use of accessories on the activity of upper limb muscles during manual wheelchair propulsion

Introduction. Wheelchair configuration is an important factor influencing the ergonomics of the user–device interface and, from a biomechanical point of view, small changes in chair setup may have a positive influence on the demand on the upper limbs during manual propulsion. This study aimed to investigate the influence of the position of the rear wheels’ axle and the use of accessories on the activity of upper limb muscles during manual wheelchair propulsion. Methods. Electromyography signals of the biceps, triceps, anterior deltoids and pectoralis major were collected for 11 able-bodied subjects in a wheelchair propulsion protocol with four different wheelchair configurations (differing in axle position and the use of accessories) on a straightforward sprint and a slalom course. Results. With accessories, moving the axle forward led to a decrease in the activity of all muscles in both the straightforward sprint (significant differences in triceps, anterior deltoids and biceps) and the slalom course (significant difference in anterior deltoids and biceps). However, when propelling the chair without accessories, no difference was found related to axle position. Conclusion. Changes in wheelchair configuration can influence the ergonomics of manual wheelchair propulsion. Reducing the biomechanical loads may benefit users’ mobility, independence and social participation.

Activity of upper limb and trunk muscles during power walking

Background: Arm swing is deliberately emphasized during power walking, a popular aerobic fitness exercise. Electromyographic (EMG) activation curves of arm and shoulder muscles during power walking have not yet been examined. Aim: To describe the amount and pattern of EMG activity of upper limb muscles during power walking. Data are compared to normal walking and jogging. Method: Twenty volunteers were examined on a treadmill at 6 km/h during (a) normal walking, (b) power walking, (c) jogging. EMG data were collected for the trapezius (TRAP), anterior (AD) and posterior deltoid (PD), biceps (BIC), triceps (TRI), latissimus dorsi (LD) and erector spinae (ES) muscles. Results: Activity of four muscles (AD, BIC, PD, TRAP) was three- to fivefold stronger during power walking than normal walking. Smaller significant increases involved the TRI, LD and ES. Two muscles (AD, TRAP) were more active during power walking than running. Normal walking and power walking involved similar EMG patterns of PD, LD, ES, while EMG patterns of running and walking differed. Interpretation: Emphasizing arm swing during power walking triples the EMG activity of upper limb muscles, compared to normal walking. Similar basic temporal muscle activation patterns in both modes of walking indicate a common underlying motor program.

Activity of upper limb and trunk muscles during power walking

<p>Background: Arm swing is deliberately emphasized during power walking, a popular aerobic fitness exercise. Electromyographic (EMG) activation curves of arm and shoulder muscles during power walking have not yet been examined. Aim: To describe the amount and pattern of EMG activity of upper limb muscles during power walking. Data are compared to normal walking and jogging. Method: Twenty volunteers were examined on a treadmill at 6 km/h during (a) normal walking, (b) power walking, (c) jogging. EMG data were collected for the trapezius (TRAP), anterior (AD) and posterior deltoid (PD), biceps (BIC), triceps (TRI), latissimus dorsi (LD) and erector spinae (ES) muscles. Results: Activity of four muscles (AD, BIC, PD, TRAP) was three- to fivefold stronger during power walking than normal walking. Smaller significant increases involved the TRI, LD and ES. Two muscles (AD, TRAP) were more active during power walking than running. Normal walking and power walking involved similar EMG patterns of PD, LD, ES, while EMG patterns of running and walking differed. Interpretation: Emphasizing arm swing during power walking triples the EMG activity of upper limb muscles, compared to normal walking. Similar basic temporal muscle activation patterns in both modes of walking indicate a common underlying motor program. </p>

The forearm positioning changes electromyographic activity of upper limb muscles and handgrip strength in the task of pushing a load cart

The aim of the present study was to analyse the electromyographic activity of the upper limb muscles as well as the handgrip strength during the activity of pushing a load cart. Eighteen healthy male right-handed volunteers (21.50 ± 2.77 years old) took part in the study. Electrodes were placed on upper trapezius fibres, brachial biceps, brachial triceps, and extensors and flexors of wrist and fingers. The original handle of the load cart was replaced by two handgrip systems mounted on load cells, thus allowing the handgrip strength to be measured according to the wrist position variation, that is, wrists in neutral position with pronated forearm (WN-PF) or in ulnar deviation with forearm in neutral position (WUD-NF). The signals generated by the load cells during manoeuvre of the load cart and the electromyographic signals were simultaneously captured. Signal processing was performed by using a specific routine developed for analysis of root mean square (RMS) and median frequency (MF). Greater handgrip strength occurred in WN-PF position. In maximal isometric contraction, the RMS of the flexors and extensors showed greater electromyographic activity in WN-PF (intra-muscles) and extensors position (inter-muscles). Decreased handgrip strength in the latter stages of the circuit, with variation of the RMS and MF of all muscles tested. One can conclude that electromyographic activity and handgrip strength are both affected during the phases of an elliptical displacement of the load cart.

The effect of arm weight support on upper limb muscle synergies during reaching movements

BackgroundCompensating for the effect of gravity by providing arm-weight support (WS) is a technique often utilized in the rehabilitation of patients with neurological conditions such as stroke to facilitate the performance of arm movements during therapy. Although it has been shown that, in healthy subjects as well as in stroke survivors, the use of arm WS during the performance of reaching movements leads to a general reduction, as expected, in the level of activation of upper limb muscles, the effects of different levels of WS on the characteristics of the kinematics of motion and of the activity of upper limb muscles have not been thoroughly investigated before.MethodsIn this study, we systematically assessed the characteristics of the kinematics of motion and of the activity of 14 upper limb muscles in a group of 9 healthy subjects who performed 3-D arm reaching movements while provided with different levels of arm WS. We studied the hand trajectory and the trunk, shoulder, and elbow joint angular displacement trajectories for different levels of arm WS. Besides, we analyzed the amplitude of the surface electromyographic (EMG) data collected from upper limb muscles and investigated patterns of coordination via the analysis of muscle synergies.ResultsThe characteristics of the kinematics of motion varied across WS conditions but did not show distinct trends with the level of arm WS. The level of activation of upper limb muscles generally decreased, as expected, with the increase in arm WS. The same eight muscle synergies were identified in all WS conditions. Their level of activation depended on the provided level of arm WS.ConclusionsThe analysis of muscle synergies allowed us to identify a modular organization underlying the generation of arm reaching movements that appears to be invariant to the level of arm WS. The results of this study provide a normative dataset for the assessment of the effects of the level of arm WS on muscle synergies in stroke survivors and other patients who could benefit from upper limb rehabilitation with arm WS.

초음파 도자를 쥐는 방법이 팔 근육의 근활성도에 미치는 영향

This study examined differences in the activity of upper limb muscles according to how an ultrasound head is gripped. Twenty-two adult males were participated in the study. Each participant was asked to apply ultrasound treatment on to a lump of pork meat by two different ultrasound head grip patterns: spherical and cylindrical grips. Muscle activity was measured in the extensor carpi radialis longus (ECRL), flexor carpi ulnaris (FCU), and pronator teres (PT), triceps brachii (TB), middle deltoid (MD), and upper trapezius (UT) muscles. There were no significant differences in the EMG signals of any muscle according to the ultrasound head grip pattern (p>.05). There were significant differences in the EMG signal of each type of muscle (p

꽃꽂이 작업의 관절가동범위와 근육활성도 측정 및 상지기능 향상을 위한 적용사례

본 연구는 신체재활을 위해 다양한 꽃꽂이 작업들을 이용하기 위해서 꽃꽂이 작업 시 주로 사용되는 작업들을 분류하고, 각 작업 수행 시 사용되는 상지의 관절가동범위와 근육 활성도를 측정하였다. 또한 꽃꽂이 작업 시 상지의 관절 가동범위와 근육활성도 측정결과를 근거로 뇌졸중 환자의 상지기능 향상을 위한 꽃꽂이 프로그램을 개발하여, 실제 임상현장에서 적용하여 그 효과를 조사하였다. 상지 움직임을 정량적으로 분석하기 위해 주요한 꽃꽂이 작업을 분류한 다음, 작업 분석을 토대로 8가지 꽃꽂이 기본 작업(자르기 1, 굵은 줄기; 자르기 2, 가는 줄기; 꽂기 1, 긴 줄기; 꽂기 2, 짧은 줄기; 말기; 관엽 이용; 휘기 1, 굵은 줄기; 휘기 2, 가는 줄기; 감기, 절화용 와이어 이용)을 재분류하였다. 강원도 소재 대학의 8명의 남학생(평균 연령 <TEX>$24.1{\pm}2.5$</TEX>세)들이 8가지 꽃꽂이 작업을 수행하는 동안 삼차원 실시간 동작 분석 시스템과 근 전도 측정기를 이용하여 상지의 관절가동범위와 각 근육부위별 활성도를 각각 측정하였다. 이 측정결과를 토대로 상지기능 향상을 위한 꽃꽃이 프로그램을 개발하여, 서울시 소재 재활병원에 입원한 뇌졸중 환자들을 대상으로 실시하였다. 참여대상자들의 의사에 따라 4명은 원예치료군에 나머지 4명은 작업치료군에 배정되었다. 원예치료는 1일 2회(총 33회기)로 실시되었으며, 프로그램 전과 후에 뇌졸중 환자들의 상지기능 평가를 위해서 관절가동범위와 장악력 및 전반적인 상지기능평가가 수행되었다. 꽃꽂이 작업 수행 시 어깨관절은 자르기 1 작업에서 관절가동범위의 변화가 가장 큰 것으로 나타났고, 팔꿈치 관절은 감기 작업에서, 손목부위 관절은 휘기 1 작업에서 가장 큰 관절가동 범위를 나타냈다(P < 0.001). 수행된 꽃꽂이 작업에 따라 상지 근육의 부위별 근육 활성도는 다양한 변화를 보였으며, 한 가지 작업에 대해 여러 부위의 근육들이 동시에 사용되었다(P < 0.001). 또한 같은 방법으로 수행하는 작업일지라도 재료의 굵기나 길이에 따라 관절가동범위와 근수축의 차이가 나타났다(P < 0.001). 뇌졸중 환자의 상지기능 향상을 위해 실시된 꽃꽂이 작업을 이용한 원예치료 프로그램은 뇌졸중 환자들의 상지(어깨, 팔꿈치, 손목관절)의 가동범위와 장악력 및 전반적인 상지 기능에 긍정적인 영향을 미치는 것으로 나타났다. 따라서 본 연구는 꽃꽂이의 주요 작업을 이용하여 특정 신체부위의 기능향상이 필요한 대상자의 재활치료를 위한 프로그램 개발에 유용한 기초자료를 제시하였다. 추가적으로 실제 재활환자의 상태에 따라 효율적인 맞춤형 원예치료 프로그램을 개발하여 그 효과를 규명하는 연구가 필요할 것이다. The objectives of this study were to measure the range of motion for joints and muscle activation of upper limb for flower arrangement tasks for physical rehabilitation and to test horticultural therapy programs using flower arrangement tasks for improving upper limb function of the patients with stroke. Major flower arrangement tasks were classified with eight tasks (cutting 1, thick stem; cutting 2, thin stem; fixing 1, long stem; fixing 2, short stem; rolling a leaf; bending 1, thick stem; bending 2, thin stem; and winding, using a wire) based on the occupational analysis. When eight male university students (mean age <TEX>$24.1{\pm}2.5$</TEX> years) conducted the eight flower arrangement tasks, range of motion for joints and muscle activation of upper limb were measured by a 3D motion analyzer and electromyography, respectively. Based on the results of the range of motion and muscle activation of upper limb, horticultural therapy programs using flower arrangement tasks (total 33 sessions) for improving upper limb function of the patients with stroke was conducted at a rehabilitation hospital, Seoul, South Korea and then the range of motion, grip strength, and upper limb function of the patients were tested. Among the eight flower arrangement tasks, cutting 1, winding, and bending 1 induced the highest value for the range of motion in joints of shoulder, elbow, and wrist, respectively (P < 0.001). In terms of muscle activation, eight flower arrangement tasks performed in this study showed various patterns of muscle activation and several muscles were simultaneously used for each task (P < 0.001). In addition, thickness and length of the materials used in a task had a prominent effect on the range of motion for joints and muscle activation of upper limb (P < 0.001). The stroke patients had positive effects for their range of motion of upper limb (shoulder, forearm, and elbow), grip strength, and overall upper limb function through the horticultural therapy program. Thus, this study suggested that flower arrangement tasks would be a potential horticultural activity for physical rehabilitation program. It would be interesting to apply a customized horticultural therapy program using flower arrangement tasks according to the symptoms of patient for physical rehabilitation.

Muscle Activity of Upper Limbs During Bimanual Driving Tasks

Muscle Activity of Upper Limbs During Bimanual Driving Tasks

Activity of upper limb muscles during human walking

The EMG activity of upper limb muscles during human gait has rarely been studied previously. It was examined in 20 normal volunteers in four conditions: walking on a treadmill (1) with unrestrained natural arm swing (Normal), (2) while volitionally holding the arms still (Held), (3) with the arms immobilized (Bound), and (4) with the arms swinging in phase with the ipsilateral legs, i.e. opposite-to-normal phasing (Anti-Normal). Normal arm swing involved weak rhythmical lengthening and shortening contractions of arm and shoulder muscles. Phasic muscle activity was needed to keep the unrestricted arms still during walking (Held), indicating a passive component of arm swing. An active component, possibly programmed centrally, existed as well, because some EMG signals persisted when the arms were immobilized during walking (Bound). Anti-Normal gait involved stronger EMG activity than Normal walking and was uneconomical. The present results indicate that normal arm swing has both passive and active components.

Quadrupedal coordination of bipedal gait: implications for movement disorders

During recent years, evidence has come up that bipedal locomotion is based on a quadrupedal limb coordination. A task-dependent neuronal coupling of upper and lower limbs allows one to involve the arms during gait but to uncouple this connection during voluntarily guided arm/hand movements. Hence, despite the evolution of a strong cortico-spinal control of hand/arm movements in humans, a quadrupedal limb coordination persists during locomotion. This has consequences for the limb coordination in movement disorders such as in Parkinson's disease (PD) and after stroke. In patients suffering PD, the quadrupedal coordination of gait is basically preserved. The activation of upper limb muscles during locomotion is strong, similar as in age-matched healthy subjects although arm swing is reduced. This suggests a contribution of biomechanical constraints to immobility. In post-stroke subjects a close interactions between unaffected and affected sides with an impaired processing of afferent input takes place. An afferent volley applied to a leg nerve of the unaffected leg leads to a normal reflex activation of proximal arm muscles of both sides. In contrast, when the nerve of the affected leg was stimulated, neither on the affected nor in the unaffected arm muscles EMG responses appear. Muscle activation on the affected arm becomes normalized by influences of the unaffected side during locomotion. These observations have consequences for the rehabilitation of patients suffering movement disorders.

The Comparison of Muscle Activation on Low-Reaching and High-Reaching in Patient with Stroke

[Purpose] The purpose of this study was to investigate the degree of muscle activation of the upper limb muscles during reaching movements in patients recovering from stroke. [Subjects] Nineteen hemiplegic patients participated in low-reaching and high-reaching tasks. [Methods] Changes in muscle activation resulting from performing low-reaching (reaching toward an object at the height of the knee) and high-reaching (reaching toward an object at the height of the shoulder) were measured using surface EMG. The surface electrodes were attached to the trapezius upper fibers, the deltoid anterior fibers, the deltoid middle fibers, the biceps, the triceps, the extensor carpi radialis and the flexor carpi radialis of both the paretic upper limb and the non-paretic upper limb. The independent t-test was used to compare muscle activation. [Results] Based on the results of measurements of muscle activation of the paretic upper limb, the muscle activation of the trapezius upper fibers and that of the deltoid anterior/middle fibers showed significant increases in high-reaching compared to low-reaching. However, for the non-paretic upper limb, significant increases were shown only in the trapezius upper fibers. These results indicate that, there is no difference between the muscle activation of the paretic side and that of the non-paretic side in high reaching while in low-reaching, the muscle activation values of the deltoid anterior fibers and the triceps of the non-paretic side are larger than those of the paretic side. [Conclusion] Muscle activation in reaching movements differs depending on the height of the target and we consider that these differences should be considered when therapeutic interventions are prescribed.