• PNF and Movement
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• v.19 no.3
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• pp.391-399
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• 2021

Purpose: As laptop use increases throughout the COVID-19 pandemic and its use outside of traditional workstations proliferates, it is imperative to expand the limited research available regarding ergonomic exposure. This study aimed to identify the effects of a laptop supporter on biomechanical characteristics in the wrist joint muscles of healthy young adults. Methods: This was a cross-sectional observational study design with thirty-four healthy young adults as participants. They conducted a typing exercise performed under two different conditions, which were with and without a notebook computer supporter. This study measured the biomechanical characteristics of the muscles of the wrist joints including the flexor carpi ulnaris (FCU), the flexor carpi radialis (FCR), the extensor carpi radialis longus (ECRL), and the extensor carpi ulnaris (ECU). Measurements were taken three times: before typing, immediately after typing for 30 minutes with a supporter, and immediately after typing for 30 minutes without a supporter. The statistical method to compare the three different measurement conditions was the repeated measures ANOVA. Results: The participants showed significantly different levels of dynamic stiffness in both the FCU before typing and immediately after 30 minutes of typing with a supporter, and showed significantly different levels of dynamic stiffness in the FCR before typing and immediately after 30 minutes of typing with a supporter. The dynamic stiffness level immediately after 30 minutes of typing without a supporter was significantly different than that immediately after 30 minutes of typing with a supporter. However, the muscle tone was not significantly different among the three different conditions. Conclusion: The results of this study revealed that a laptop supporter used to correct the eye level of the electronic screen increases the dynamic stiffness of the wrist joint flexors, so it is necessary to consider the neutral position of the wrist joint during typing.

• Physical Therapy Korea
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• v.14 no.3
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• pp.9-15
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• 2007

The purpose of this study was to investigate electromyographic activities of the flexor digitorum superficialis (FDS) and the flexor carpi ulnaris (FCU) by the shape of the ultrasound head. Twelve healthy subjects participated and performed ultrasound therapy with a round head and a long handled head during each 5-minute application. Electromyographic activities of the FDS and FCU were recorded by surface electrodes and normalized by maximal voluntary isometric contraction (MVIC) values. There was no difference in the muscular fatigue of FDS and FCU as determined by the shape of the ultrasound head (p>.05). Without the shape of head, the mean power frequency decreased with the time. There also was no difference in %MVIC of the FDS and FCU as determined by the shape of the ultrasound head (p>.05), but the force exerted exceeded 20%MVIC. There was however a significant difference in the amount of cumulative workload of the FDS and FCU as determined by the shape of ultrasound head (p<.05). The workload was however not affected by the shape of the ultrasound head. Constant static grasp of ultrasound transducer head during ultrasound therapy is considered a high risk factor of work-related musculoskeletal disease.

• The Journal of Korean Physical Therapy
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• v.15 no.4
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• pp.455-465
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• 2003

The purpose of this study was to describe the alteration of muscle action potential of spastic upper extremity in a patient with cerebral palsy by the water temperature. We used seven patients with cerebral palsy. Participants classified according to each group in $29^{\circ}C,\;35^{\circ}C$ by the water temperature. All subjects participated 2 session, which at least 1 week between session. The test was measured continuously pre test, post-test by thermometer and surface EMG. The following results were obtained; 1. In changes of surface temperature, wrist flexor and extensor were significantly decreased in $29^{\circ}C$ (p<0.001) group but were significantly increased $35^{\circ}C$ group(p<0.01). 2. In changes of surface temperature, wrist flexor and extensor were significantly differenced between $29^{\circ}C$ and $35^{\circ}C$ group(p<0.001). 3. In changes of muscle action potential, wrist extension antagonist were significantly increased in $29^{\circ}C$ group(p<0.05). 4. In changes of muscle action potential, wrist flexion agonist were more significantly increased in $29^{\circ}C$ group(p<0.01). 5. In changes of muscle action potential, wrist extension antagonist were significantly differenced between $29^{\circ}C$ and $35^{\circ}C$ group(p<0.05). These results lead us to the conclusion that changes of muscle action potential of spastic upper extremity in a patient with cerebral palsy were influenced by the water temperature. Therefore, a further direction of this study will be to provide more evidence that a moderate water temperature have an effect on muscle tone in a patient with cerebral palsy.

• Physical Therapy Korea
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• v.13 no.1
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• pp.38-46
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• 2006

The purposes of this study were to investigate the median frequency (MDF) between initiation and termination of muscle contraction through surface electromyographic (sEMG) analysis and to propose the basis of clinical treatment for movement problems in early hemiparetic upper limbs. Thirteen patients who had stroke with onset less than 3 months prior to the study and seven control subjects participated in the study. The median frequency in initiation and termination of muscle contraction was recorded from wrist flexor and extensor muscles using the sEMG, with 3 second beeper signals, during maximal isometric wrist flexion and extension. Flexion and extension must be done as quickly and forcefully as possible. The results of the study were as follows: 1. The MDF of the onset and offset sections were significantly lower on the paretic than the nonparetic and control sides. 2. The MDF of the offset section significantly decreased on the paretic and nonparetic sides. Consequently, this study showed that the lowering of the MDF was due to the hemiparetic wrist motor impairment and muscle weakness. These results are also related to Fugl-Meyer motor assessment (FMA) scores in hemiparetic upper limbs. This study also suggests that since muscle weakness of early stroke patients affects the functional decrease of upper limbs, further studies must focus on the treatment to improve muscle agility and muscle fiber recruitment efficiency that can induce the functional recovery correlated to motor control.

• Journal of The Korean Society of Integrative Medicine
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• v.3 no.2
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• pp.1-8
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• 2015

Purpose: This study was conducted to know the evidence case to assessment about literatures of extensor carpi radialis therapeutic strategy of tennis elbow about dysfunction wrist extension with anatomy, biomechanic and function. Method: Patient was received the physical therapy program with medication for two weeks. Physical therapy program consists of strengthening exercise, stretching exercise and extracopereal shock wave therapy. Results: Patients could do computer and house works at three weeks significant with improved pain. The amounts used repetitive muscle was reduced slowly over a period of a day or two days for wrist moving. Wrist flexor strengthening exercise and could reduced the wrist extensor injury. Conclusion: Clinicians certainly realized biomechanic effects and anatomy of extensor carpiradialis and elbow joint.

• Journal of the Korean Society of Physical Medicine
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• v.13 no.1
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• pp.1-9
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• 2018

PURPOSE: This study investigated the neurophysiological and behavioral adaptation during one or both hands movement in chronic stroke patients. METHODS: The study included sixteen hemiplegic stroke patients. Neurophysiological data (brain activation and muscle activation) were examined by electroencephalography (EEG) and electromyography (EMG), and behavioral adaptation was examined by wrist extension angle during wrist extension with one hand or both hands. Outcome variables of one hand or both hands were; mu rhythm of the EEG, EMG amplitude of wrist extensor and flexor muscles, and wrist angle of Myomotion 3D motion analysis. RESULTS: Our results revealed that wrist extension angle was significant increased during both hands movement compared to one hand movement (p<.05). Furthermore, in affected sensorimotor area, there was significant increase in the brain activation during both hands movement compared to one hand movement (p<.05). However, there was no significant different between one hand and both hands movement in muscle activation (p>.05). CONCLUSION: According to the findings of this experiment, bilateral arm movement improved brain activity on affected sensorimotor area and wrist extension angle. Therefore, we suggest that bilateral arm movement would positive effect on stroke rehabilitation in terms of increase in brain activation on affected motor area and wrist extension during bilateral arm movement.

• Proceedings of the ESK Conference
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• 1994.04a
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• pp.49-51
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• 1994

The aims of this study were first to determine the influence of vibration displacement amplitude $(200{\mu}m, 300{\mu}m peak-to-peak)$ at selected frequencies (40-200Hz) on a commonly observed but often undesired motor response elicited bylocal vibratory stimulation, the Tonic Vibration Reflex (TVR). Second, to determine the degree of synchronization of motor unit (MU) activity with vibratory stimuli. Vibration was applied to the distal tendons of the hand flexor muscles. Changes in root- mean-square electromyographic (EMG) activity of the finger and wrist flexor muscles were analyzed both as a function of their initial contraction level (0%, 10%, 20% of the maximal voluntarycontraction: MVC) and as a function of the vibration parameters. The results indicate that the TVR increased with the initial muscle contraction up to 10% MVC: The TVR increased with vibration frequency up to 100-150 Hz and decreases beyond; A significant increase of the TVR with vibration displacement amplitude was observed only for the wrist flexor muscle; MU synchronization at vibration frequency (VF) was found more often in the low frequency range $(f{\leq}100 Hz)$ and tended todecrease beyond; In the high frequency range $(f{\geq}120 Hz)$, MU activity at subharmonic frequency was predominant; The "cut-off" frequency of the synchronization with VF was neither affected by the vibration displacement amplitude nor initial muscle contraction level. The surface EMG turned out to be a useful means to analyze MU synchronization since it is noninvasive, and it can be easily used for analysis of different muscle contraction levels, while single MU technique might have some difficulties at high muscle contraction levels. Furthermore, these results indicate that high frequencyvibration (f>150 Hz) tends to induce less muscle/tendon stress and MU synchronization. Such remarks are of importance for the design of hand-held vibrating tools.ing tools.

• Clinical Pain
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• v.18 no.2
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• pp.107-110
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• 2019

Flexor carpi radialis (FCR) muscle is located in the forearm anteriorly that runs through a synovial fibro-osseous tunnel in the forearm. We described a case of FCR tendon rupture due to repetitive overuse injury. A 55-year-old man, right-hand dominant, presented with right forearm pain and swelling which started 3 days ago while playing amateur golf. Focal tenderness and bruising over volo-ulnar region of the right forearm were examined. Plain radiographs showed soft tissue edema around lesion area and no detectable fracture. Ultrasonography showed multiple hypoechoic lesions suspected as hematoma of the flexor muscle group. After done magnetic resonance imaging, he was diagnosed with rupture of FCR tendon at proximal origin and strain of flexor digitorum superficialis and palmaris longus muscle. He received compressive dressing and restriction of wrist range of motion for three weeks. Two months later, remaining traces of lesions were observed at the follow-up ultrasonography and the pain disappeared.

• International Journal of Internet, Broadcasting and Communication
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• v.12 no.1
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• pp.81-89
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• 2020

The purpose of this study is to investigation the effects of functional compression clothing on muscle function by comparing the iEMG response of muscle during exercise according to the wearing of taping applied functional clothing. Six men in their twenties in Chungcheongnam-do were selected for the study. Resistance exercise was performed by cross-distributing the conditions of wearing and not wearing functional clothing. Resistance exercises for iEMG measurements are biceps curl, wrist curl, reverse wrist curl, kickback and push-up. iEMG measurement muscles were the biceps brachii, triceps brachii, extensor carpi ulnaris, flexor carpi radialis. During biceps curl exercise, the iEMG of triceps brachii, biceps brachii wearing condition was lower than the non-wearing condition. During kickback exercise, the iEMG of triceps brachii, extensor carpi ulnaris wearing condition was lower than the non-wearing condition. During reverse wrist curl exercise, the iEMG of extensor carpi ulnaris wearing condition was lower than the non-wearing condition. During wrist curl exercise, the iEMG of flexsor biceps brachii, carpi radialis wearing condition was lower than the non-wearing condition. During push-up exercise, the iEMG of triceps flexsor biceps brachii, carpi radialis, brachii, biceps brachii non-wearing condition was lower than the wearing condition.

• Journal of Korean Neurosurgical Society
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• v.62 no.1
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• pp.90-95
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• 2019

Objective : Anomalous muscles of the wrist are infrequently encountered during carpal tunnel surgery. Anatomic variants of the palmaris longus (PL), flexor digitorum superficialis, lumbricalis and abductor digiti minimi (ADM) have been reported but are usually clinically insignificant. Anomalies of the wrist muscles, encountered during endoscopic carpal tunnel surgery have rarely been described. I conducted this study to evaluate muscular anomalies of the volar aspect of the wrist, encountered during endoscopic carpal tunnel surgery. Methods : I studied a consecutive series of 1235 hands in 809 patients with carpal tunnel syndrome who underwent single-portal endoscopic carpal tunnel release (ECTR) from 2002 to 2014. Nine hundred seventy-three hands in 644 patients who had minimal 6-month postoperative follow-up were included in the study. The postoperative surgical outcome was assessed at least 6 months after surgery. Results : In eight patients, anomalous muscles were found under the antebrachial fascia at the proximal wrist crease and superficial to the ulnar bursa, passing superficial to the transverse carpal ligament. Those anomalous muscles were presumed to be variants of the PL or accessory ADM muscle, necessitating splitting and retraction to enter the carpal tunnel during the ECTR procedure. Other muscle anomalies were not seen within the carpal tunnel on the endoscopic view. The surgical outcome for all eight wrists was successful at the 6-month postoperative follow-up. Conclusion : Carpal tunnel surgeons, especially those using an endoscope should be familiar with unusual findings of anomalous muscles of the wrist because early recognition of those muscles can contribute to avoiding unnecessary surgical exploration and unsuccessful surgical outcomes.