OBJECTIVETo observe the effects of forearms devascularization on the volt-ampere (V-A) characteristics of Neiguan (PC 6) and Taiyuan (LU 9) so as to investigate the relationship among functions of acupoints, qi and blood in human body and V-A characteristics of acupoints.

METHODSEither forearms of 23 healthy volunteers were devascularized and the changes of V-A characteristics in ipsilateral Neiguan (PC 6) and Taiyuan (LU 9) in normal and devascularization statuses were detected by home-made intelligent V-A detecting system.

RESULTSCompared with the normal status, both range-increasing and range-decreasing V-A areas of Neiguan (PC 6) and Taiyuan (LU 9) were significantly increased in devascularization status (P < 0.05, P < 0.01), and the change rates of these two V-A areas of Neiguan (PC 6) were larger than those of Taiyuan (LU 9) (both P < 0.05). The inertia areas of Neiguan (PC 6) but not Taiyuan (LU 9) became significantly larger after devascularization (P < 0.01).

CONCLUSIONThe changes in V-A characteristics of Neiguan (PC 6) and Taiyuan (LU 9) can reflect the alteration of local blood supply, and Neiguan (PC 6) is more sensitive to changes of blood flow than Taiyuan (LU 9).

Acupuncture Points ; Adult ; Blood Circulation ; Electrophysiology ; Female ; Forearm ; blood supply ; physiology ; Humans ; Male ; Young Adult

The purpose of this study was to examine whether repetitive muscle tasks in low weight load might influence the fatigue of forearm muscles, and to identify ergonomic risk factors of forearm muscle fatigue in these tasks. Sixteen healthy male volunteers performed eight wrist extensions in different frequency, weight and angle loads while being instructed to keep a dominant upper limb posture as constant as possible. Surface electromyograph (sEMG) was recorded from right extensors digitorium (ED), flexor carpi radialis (FCR), flexor carpi ulnaris (FCU) and extensor carpi ulnaris (ECU) during the task performance. Our results showed that mean power frequency (MPF) and median frequency (MF) values of ED, FCR and FCU were significantly lower (P<0.05) at high frequency load level than at low load level. However, MPF and MF values of ED were significantly lower (P<0.01) in higher load groups of frequency, angle and weight than in lower load groups. These results indicated that the fatigue of muscles varied in the same task, and the number-one risk factor of ECU, ED and FCR was angle load.
Cumulative Trauma Disorders/complications ; Cumulative Trauma Disorders/*physiopathology ; Electromyography ; Forearm/*physiology ; Muscle Fatigue/*physiology ; Muscle, Skeletal/*physiopathology ; Young Adult

OBJECTIVETo study the anatomical and biomechanical features of the interosseous membrane (IOM) of the cadaveric forearm.

METHODSTen radius-IOM-ulna structures were harvested from fresh-frozen cadavers to measure the length, width and thickness of the tendinous portion of IOM. Then, the tendinous portion was isolated along with the ulnar and radial ends to which the tendon attached after measurement. The proximal portion of the radius and the distal portion of the ulna were embedded and fixed in the dental base acrylic resin powder. The embedded specimen was clamped and fixed by the MTS 858 test machine using a 10 000 N load cell for the entire tensile test. IOM was stretched at a speed of 50 mm/min until it was ruptured. The load-displacement curve was depicted with a computer and the maximum load and stiffness were recorded at the same time.

RESULTSThe IOM of the forearm was composed of three portions: central tendinous tissue, membranous tissue and dorsal affiliated oblique cord. IOM was stretched at a neutral position, and flexed at pronation and supination positions. The tendinous portion of IOM was lacerated in 6 specimens when the point of the maximum load reached to 1021.50 N+/-250.13 N, the stiffness to 138.24 N/m+/-24.29 N/m, and the length of stretch to 9.77 mm+/-1.77 mm. Fracture occurred at the fixed end of the ulna before laceration of the tendinous portion in 4 specimens when the maximum load was 744.40 N+/-109.85 N, the stiffness was 151.17 N/m+/-30.68 N/m, and the length of the stretch was 6.51 mm+/-0.51 mm.

CONCLUSIONSThe IOM of the forearm is a structure having ligamentous characteristics between the radius and the ulna. It is very important for maintenance of the longitudinal stability of the forearm. The anatomical and biomechanical data can be used as an objective criterion for evaluating the reconstructive method of IOM of the forearm.

Biomechanical Phenomena ; Cadaver ; Forearm ; anatomy & histology ; physiology ; Humans ; Membranes ; anatomy & histology ; physiology ; Radius ; anatomy & histology ; Ulna ; anatomy & histology

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

As is well known that the quality of training samples directly influence the recognizing ability of neural network. In this paper, we introduce a method for solving the problem of how to classify the pattern of forearm by obtaining typical samples. At first, the original samples were pretreated by using the membership class function that can improve the quality of cluster sample. Then, the center of clustering could be gained by using the method of clustering and the typical sample was obtained. Based on this method, we can get the typical sample that corresponds with the movements of stretch of arm and fold of arm. We can make them as the training sample of the BP network to classify the pattern of forearm. The experiment indicates that this measure can improve the point of identification.
Algorithms ; Cluster Analysis ; Electromyography ; methods ; Forearm ; physiology ; Humans ; Neural Networks (Computer) ; Pattern Recognition, Automated ; methods ; Signal Processing, Computer-Assisted

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

OBJECTIVE: To provide the evidences for the choice of normal reference value of nerve conduction velocity (NCV) in clinical forensic appraisal. METHODS: One hundred and fourteen cases with normal peripheral nerve and 155 cases with injured peripheral nerve were collected. The NCV of homonymous nerves in two limbs were detected. In the normal cases, the NCV of the left limbs were used as the normal reference values. The NCV of the right limbs were compared with that of left limbs, the commendatory normal reference values from Beijing Xiehe Hospital and Shanghai Huashan Hospital. In the injured cases, the results of NCV in injuried limbs were compared with the results of healthy limbs and the reference values from Beijing Xiehe Hospital and Shanghai Huashan Hospital. RESULTS: In the normal group, there was no statistical difference between the left and right limbs in NCV results of homonymous nerve (P > 0.05). The false positive rates (FPR) were 0, 11.4% and 5.2% for three choices normal reference respectively. The false negative rates (FNR) were 0, 9.7% and 12.3% for three choices normal reference in injuried group. Thee false negative cases were all slight nerve injury. CONCLUSION The reference value of self-control method could decrease the FPR of normal cases and FNR of injured cases. In clinical forensic appraisal of peripheral nerve, the nerve condition study results from healthy homonymous nerve should be regarded as the reference value at first, supplemented by reference values from clinical labs.
Adolescent ; Adult ; Electrodiagnosis/methods* ; Forearm ; Forensic Medicine ; Humans ; Median Nerve/physiology* ; Middle Aged ; Neural Conduction/physiology* ; Peripheral Nerve Injuries/diagnosis* ; Peripheral Nerves/physiology* ; Reference Values ; Ulnar Nerve/physiology* ; Young Adult

This study was designed to investigate the incidence of lateral root of the ulnar nerve through cadaveric dissection and to analyze its impact on myotomes corresponding to the flexor carpi ulnaris (FCU) assessed by electrodiagnostic study. Dissection of the brachial plexus (BP) was performed in 38 arms from 19 cadavers, and the connecting branches between the lateral cord and medial cord (or between lateral cord and ulnar nerve) were investigated. We also reviewed electrodiagnostic reports from January 2006 to May 2008 and selected 106 cases of single-level radiculopathy at C6, C7, and C8. The proportion of abnormal needle electromyographic findings in the FCU was analyzed in these patients. In the cadaver study, branches from the lateral cord to the ulnar nerve or to the medial cord were observed in 5 (13.1%) of 38 arms. The incidences of abnormal electromyographic findings in the FCU were 46.2% (36/78) in C7 radiculopathy, 76.5% (13/17) in C8 radiculopathy and 0% (0/11) in C6 radiculopathy. In conclusion, the lateral root of the ulnar nerve is not an uncommon anatomical variation of the BP and the FCU commonly has the C7 myotome. Needle EMG of the FCU may provide more information for the electrodiagnosis of cervical radiculopathy and brachial plexopathy.
Brachial Plexus/anatomy & histology/physiology ; Brachial Plexus Neuropathies/diagnosis ; Cadaver ; Electrodiagnosis/methods ; Electrophysiology/*methods ; Female ; Forearm/*anatomy & histology ; Humans ; Male ; Muscle, Skeletal/*innervation/physiology ; Radiculopathy/diagnosis ; Ulnar Nerve/*anatomy & histology/physiology

OBJECTIVETo explore the biological reaction of swine acellular dermal matrix as a filling material for body surface deformity.

METHODSXenogenic acellular dermal matrix was implanted into the hypoderm of rabbits. The implants were measured and observed with pathological and transmission electron microscopic technique at regular times. The results were compared with implantation of autologous dermis and swine dermis.

RESULTSThe implanted xenogenic acellular dermal matrix and autologous dermis had slight inflammatory reaction. At 2 weeks there were fibroblasts and capillaries in the implants. The absorptivity of the xenogenic acellular dermal matrix was lower than the swine dermis. The xenogenic acellular dermal matrix was used in 2 clinical cases and obtained good result.

CONCLUSIONThe xenogenic acellular dermal matrix is an ideal material with good compatibility feature and low absorptivity.

Animals ; Biocompatible Materials ; metabolism ; Cleft Lip ; surgery ; Dermis ; physiology ; transplantation ; ultrastructure ; Female ; Forearm ; abnormalities ; surgery ; Graft Survival ; physiology ; Humans ; Male ; Microscopy, Electron ; Rabbits ; Skin Transplantation ; methods ; Subcutaneous Tissue ; surgery ; Swine ; Transplantation, Heterologous

OBJECTIVETo investigate three-dimensional kinematics of the superficial and deep portion of triangular fibrocartilage complex (TFCC) in different parts of the forearm rotation.

METHODSSix wrists of 6 volunteers were used to obtain CT scans at different positions of the wrist. The wrists were scanned from 90 degrees of pronation to 90 degrees of supination at an interval of 30 degrees. The 3-dimensional radius and ulna were reconstructed with customized software and changes in length of the superficial and deep portion of TFCC during forearm rotation.

RESULTSIn forearm pronation, the superficial dorsal portion and the deep palmar portion of the TFCC were tight. While the superficial palmar portion and the deep dorsal potion of the TFCC were lax. In supination, the changes in length of all these fibers were reverse.

CONCLUSIONSIn forearm rotation one portion fibers of dorsal TFCC and one portion fibers of palmar TFCC are tight, and this mechanism controls stability during DRUJ rotation.

Adult ; Biomechanical Phenomena ; Female ; Forearm ; physiology ; Humans ; Imaging, Three-Dimensional ; Male ; Pronation ; Radiography ; Radius ; diagnostic imaging ; Supination ; Triangular Fibrocartilage ; diagnostic imaging ; Ulna ; diagnostic imaging ; Wrist Joint ; diagnostic imaging ; Young Adult