This study proposes a new method for measuring upper limb movement using a bio-impedance technique. Bio-impedance and joint angle were simultaneously measured during the wrist and elbow movements of 12 normal subjects. The joint angles of the wrist and elbow were estimated by measuring the bio-impedances of the forearm and upper arm, respectively. Although the measured bio-impedances on upper limbs varied among individuals, changes in the bio-impedances and joint angles of the wrist and elbow during their extension and flexion were very highly correlated, having correlation coefficients of 0.96 +/- 0.04 and -0.98 +/- 0.02, respectively. The reproducibilities of wrist and elbow bio-impedance changes were 2.1 +/- 1.0% and 1.8 +/- 1.0%, respectively. Since the proposed method is not restricted by size or the duration of measurements, it is expected to be useful for the analysis of athletic movement.
Elbow/*physiology ; Electric Impedance ; Human ; Movement ; Reproducibility of Results ; Wrist/*physiology

It is the functional connectivity between motor cortex and muscle that directly relates to the rehabilitation of the dysfunction in upper limbs and neuromuscular activity status, which can be detected by electroencephalogram-electromyography (EEG-EMG) coherence analysis. In this study, based on coherence analysis method, we process the acquisition signals which consist of 9 channel EEG signal from motor cortex and 4 channel EMG signal from forearm, by using 4 groups of hand motions in the healthy subjects, including flexor digitorum, extensor digitorum, wrist flexion, and wrist extension. The results showed that in the β-band, the coherence coefficients between C3 and flexor digitorum (FD) was greater than extensor digitorum (ED) in the right hand flexor digitorum movement; the coherence coefficients between C3 and ED was greater than FD in the right hand extensor digitorum movement; the coherence coefficients between C3 and flexor carpi ulnaris (FCU) was greater than extensor carpi radialis (ECR) in the right hand wrist flexion movement; the coherence coefficients between C3 and ECR was greater than FCU in the right hand wrist extension movement. This analysis provides experimental basis to explore the information decoding of hand motion based on corticomuscular coherence (CMC).
Electroencephalography ; Electromyography ; Healthy Volunteers ; Humans ; Motor Cortex ; physiology ; Movement ; Muscle, Skeletal ; physiology ; Range of Motion, Articular ; Wrist ; physiology ; Wrist Joint ; physiology

Kinematics has been successfully used to describe body motion without reference to the kinetics (or forces causing the motion). In this article, both the theory and applications of the matrix method are provided to describe complex human motion. After the definition of a Cartesian coordinate frame is introduced, the description of transformations between multiple coordinate frames is given; the decomposition of a transformation matrix into anatomical joint motion parameters (e.g. Euler angles) is then explained. The advantages of the matrix method are illustrated by three examples related to biomechanical studies. The first describes a reaching and grasping task in which matrix transformations are applied to position the hand with respect to an object during grasping. The second example demonstrates the utility of the matrix method in revealing the coupling motion of the wrist between flexion-extension and radial-ulnar deviation. The last example highlights the indispensable use of the matrix method for the study of knee biomechanics, including the description of knee joint kinematics during functional activities and determination of in-situ ligament forces using robotic technology, which has advanced our understanding of the functions of the cruciate ligaments to knee joint kinematics. It is hoped that the theoretical development and biomechanical application examples will help the readers apply the matrix method to research problems related to human motion.
Biomechanical Phenomena ; methods ; Humans ; Knee ; physiology ; Motion ; Movement ; physiology ; Wrist ; physiology

OBJECTIVETo explore the characteristics of light propagation along the Pericardium Meridian and its surrounding areas at human wrist by using optical experiment and Monte Carlo method.

METHODSAn experiment was carried out to obtain the distribution of diffuse light on Pericardium Meridian line and its surrounding areas at the wrist, and then a simplified model based on the anatomical structure was proposed to simulate the light transportation within the same area by using Monte Carlo method.

RESULTSThe experimental results showed strong accordance with the Monte Carlo simulation that the light propagation along the Pericardium Meridian had an advantage over its surrounding areas at the wrist.

CONCLUSIONThe advantage of light transport along Pericardium Merdian line was related to components and structure of tissue, also the anatomical structure of the area that the Pericardium Meridian line runs.

Diffusion ; Humans ; Light ; Meridians ; Models, Theoretical ; Monte Carlo Method ; Optics and Photonics ; methods ; Pericardium ; physiology ; Wrist ; physiology

PURPOSE: To verify the effect of a newly-developed cylindrical type forearm brace, which was designed to give focal counterforce perpendicularly on the muscle belly of the wrist extensor. MATERIALS AND METHODS: The dominant hands of 24 (12 males, 12 females) healthy subjects were tested. Two types of forearm braces (focal cylindrical type and broad pneumatic type) were examined. The braces were applied at the extensor carpi radialis brevis, 5 to 7 cm distal to the lateral epicondyle. Two surface electrodes were attached to the proximal and distal parts of the brace. By quantitative electromyography, the mean amplitudes of voluntary extensor carpi radialis brevis contraction before and after applying each brace were recorded and analyzed. RESULTS: The mean amplitudes of the focal cylindrical brace and broad pneumatic brace were reduced significantly compared to no brace (p<0.05), with a larger reduction for the cylindrical brace than the pneumatic brace (p<0.05). There was no significant difference between the proximal and distal mean amplitudes with each brace. CONCLUSION: A cylindrical type brace decreased electromyographic activity in the wrist extensor more effectively than did the pneumatic type brace.
Adult ; *Braces ; *Electromyography ; Equipment Design ; Female ; Forearm/physiology ; Humans ; Male ; Middle Aged ; Tennis Elbow/physiopathology/therapy ; Wrist/*physiology ; Wrist Joint ; Young Adult

Adult ; Fractures, Comminuted ; etiology ; surgery ; Humans ; Humeral Fractures ; etiology ; surgery ; Male ; Wrestling ; Wrist Joint ; physiology

Objective: To investigate the regularity of sensory recovery after repairing the wounds on the wrist and back of hand with anterolateral femoral flap without nerve anastomosis. Methods: A cross-sectional study was conducted. From January 2018 to December 2020, patients who underwent free anterolateral femoral flaps without nerve anastomosis to repair wounds on the wrist and back of hand and met the inclusion criteria in Changshu Hai Yu Health Centre and Suzhou Ruihua Orthopedic Hospital were included in this study. Depending on the time interval between the day of the patient's surgery and the day of the cross-sectional survey, 80 patients were divided into 6-month group (15 males and 5 females, aged 22-63 years), 12-month group (16 males and 4 females, aged 21-65 years), 18-month group (15 males and 5 females, aged 25-61 years), and 24-month group (14 males and 6 females, aged 20-65 years), with 20 patients in each group. The area of skin and soft tissue defects after debridement ranged from 6.0 cm×4.5 cm to 18.0 cm×9.0 cm. Anterolateral femoral flaps were cut with areas of 7 cm×5 cm to 20 cm×10 cm and a thickness of 1.0 to 2.5 cm. Each transplanted flap was divided into A (proximal), B/D (bilateral), C (distal), and E (central) regions. The pain sensation, touch sensation, cold sensation, warmth sensation, and two-point discrimination (2-PD) in the aforementioned five regions and the differences in the five senses of the whole flap were tested and compared. Data were statistically analyzed with one-way analysis of variance, Fisher's exact probability test, chi-square test, or McNemar test. Results: In A region of anterolateral femoral flap without nerve anastomosis, compared with those in 6-month group, the pain sensation, touch sensation, cold sensation, and warmth sensation of flap of patients in 12-month group were significantly recovered (with χ² values of 10.10, 14.55, 12.13, and 4.29, respectively, P<0.05 or P<0.01); compared with that in 12-month group, the warmth sensation of flap of patients in 18-month group recovered significantly (χ²=5.23, P<0.05). In B region, compared with those in 6-month group, the pain sensation, touch sensation, and cold sensation of flap of patients in 12-month group recovered significantly (with χ² values of 5.58, 3.96, and 4.29, respectively, P<0.05); compared with those in 12-month group, the pain sensation, touch sensation, cold sensation, and warmth sensation of flap of patients in 18-month group recovered significantly (with χ² values of 5.58, 3.96, 7.03, and 12.38, respectively, P<0.05 or P<0.01). In C region, compared with that in 6-month group, the pain sensation of flap of patients in 12-month group recovered significantly (χ²=4.80, P<0.05); Compared with that in 12-month group, the warmth sensation of flap of patients in 18-month group recovered significantly (χ²=10.16, P<0.01). In D region, compared with those in 6-month group, the pain sensation, touch sensation, and cold sensation of flap of patients in 12-month group recovered significantly (with χ² values of 5.58, 4.29, and 3.96, respectively, P<0.05); compared with those in 12-month group, the pain sensation, touch sensation, cold sensation, and warmth sensation of flap of patients in 18-month group recovered significantly (with χ² values of 5.58, 4.29, 3.96, and 10.10, respectively, P<0.05 or P<0.01). In E region, compared with that in 6-month group, the cold sensation of flap of patients in 12-month group recovered significantly (χ²=4.80, P<0.05); compared with those in 12-month group, the pain sensation, touch sensation, and warmth sensation of flap of patients in 18-month group recovered significantly (with χ² values of 6.47, 4.91, and 9.23, respectively, P<0.05 or P<0.01). The five senses in the 5 regions of flap of patients in 24-month group were similar to those in 18-month group (P>0.05). The recovery of 2-PD in the 5 regions of flap of patients was similar between the two adjacent groups (P>0.05). In 12-month group, the recoveries of pain sensation, touch sensation, and cold sensation of flap of patients in A region were better than those in the other 4 regions (P<0.05 or P<0.01), the recovery of warmth sensation was better than that of B region, C region, and E region (P<0.05 or P<0.01); in 18-month group, the recovery of pain sensation, touch sensation, cold sensation, and warmth sensation of flap of patients in A region of was better than those in area C region (P<0.05). Compared with those in 6-month group, the pain sensation, touch sensation, and cold sensation of the whole flap of patients in 12-month group recovered significantly (with χ² values of 7.62, 7.03, and 5.58, respectively, P<0.05 or P<0.01). Compared with the 12-month group in which 10, 11, 10, and 4 patients had a recovery of pain, touch sensation, cold sensation, and warmth sensation in the whole flap, the 18-month group had significantly more patients with sensations recovered, which were 17, 17, 16, and 14, respectively (with χ² values of 5.58, 4.29, 3.96, and 10.10, respectively, P<0.05 or P<0.01). The five senses of the whole flap of patients in 24-month group were similar to those in 18-month group (P>0.05). Conclusions: In the anterolateral femoral flap without nerve anastomosis for repairing wounds on the wrist and back of hand, the sensation gradually recovered from the proximal end to the distal end. The sensation of touch, pain, and cold began to recover from 6 months after operation, and entered the stable recover period at 18 months after operation. Warmth sensation began to recover from 12 months after operation, and entered the stable recovery period at 18 months after operation. The 2-PD of most flaps was still not recovered 2-year after operation.
Male ; Female ; Humans ; Wrist ; Cross-Sectional Studies ; Touch/physiology* ; Pain ; Anastomosis, Surgical

The scaling method of the loss degree of joint motion is very common in clinical forensic medicine. However, there is no uniform criterion until now. Therefore, this had made a negative effect to ensure the impartiality and justice in law and the identification. The advantages and disadvantages of the four methods recorded in literatures by practical case, which include major and minor methods, additional methods, directive average methods, axial directive average methods, were discussed and compared. Now three basic critics about how to choosing the applicable technique in forensic medicine were supposed according to the impartiality and justice principle, scientific and objective principle, simple and easy principle. It was hoped that we can reach a consensus in our legal-medical circumscription that all of us can choose the Axial Directive Average Methods as our standard for the loss degree of joint motion, to avoid the disadvantages of this aspect.
Adult ; Forensic Medicine/methods* ; Humans ; Joints/injuries* ; Male ; Range of Motion, Articular/physiology* ; Wrist Injuries/physiopathology*

OBJECTIVETo evaluate the influence of the frequency, the weight and the motion angle on the stress and the fatigue of the forearm extensors in repetitive wrist extending at low force loading level with surface electromyography (SEMG).

METHODSSixteen male college student volunteers were recruited for the experiment. Eight tasks of wrist extending were performed for 20 minutes respectively in given weight (1.96, 4.90 N), frequency (8.0, 33.3 moves/minute) and motion angle (45 degrees, 90 degrees). The static wrist extending at the level of 20% maximum voluntary contraction (MVC) were performed before and after each task for 2 up to 3 seconds, and the SEMG signals of extensor carpi ulnaris muscle (ECU) and extensor digitorum (ED) were recorded and analyzed.

RESULTSThe weight loading level was approximately equal to 1.40% or 3.50% of the MVC force. The mean power frequency (MPF) and the median frequency (MF) were decreased with the increase of 3 kinds of loading levels. The decrease of MPF of the muscle ED was significant (P < 0.05 or P < 0.01). The MF was decreased with the increase of angle and weight loading levels (P < 0.05 or P < 0.01). The root mean square (RMS) value of SEMG could be divided into 3 or 4 groups with significant difference. All three kinds of loads had positive correlation with amplitude of SEMG according to the stepwise regression analysis.

CONCLUSIONThe fatigue level of ED is the highest. The primary load factor for the forearm extensors is the frequency followed by the weight and the angle. MF, MPF and RMS can be used as sensitive indexes for evaluating the stress and the fatigue of the forearm extensors during repetitive performance at lower force loading level.

Adolescent ; Adult ; Electromyography ; Forearm ; physiology ; Humans ; Male ; Muscle Fatigue ; physiology ; Muscle, Skeletal ; physiology ; Range of Motion, Articular ; Regression Analysis ; Workload ; Wrist Joint ; physiology

PURPOSE: The purpose of this study was to investigate the effects of passive upper arm exercise on range of motion, muscle strength, and muscle spasticity in hemiplegic patients with cerebral vascular disease. METHODS: A quasi-experimental design with nonequivalent control group was utilized. According to inclusion criteria, 25 patients were assigned to the control group with routine care, followed by 25 to the intervention group with passive exercise for 30 minutes per session, twice a day for 2 weeks. Eighteen patients in the intervention group and 17 in the control group completed the posttest measurement, including range of motion for upper arm joints, manual muscle test, and Modified Ashworth Scale for muscle spasticity. RESULTS: The intervention group had a significantly improved range of motion in the shoulder and wrist joints. No interaction effect was found for the elbow joint. No significant differences were found in muscle strength or muscle spasticity between the groups. CONCLUSION: Results of the study indicate that passive exercise safely applied for two weeks improves range of motion in joints of the upper arm in these patients. Further study with long-term follow-up is needed to verify the role of passive exercise in preventing muscle spasticity in this population.
Adult ; Aged ; Cerebrovascular Disorders/*complications ; *Exercise Therapy ; Female ; Hemiplegia/complications/*therapy ; Humans ; Male ; Middle Aged ; *Muscle Spasticity ; *Muscle Strength ; *Range of Motion, Articular ; Shoulder Joint/physiology ; Wrist Joint/physiology