To quantitatively evaluate the upper-limb spasticity of stroke patients in recovery stage, the relationship between surface electromyography (sEMG) characteristic indexes from biceps brachii and triceps brachii and the spasticity were explored, which provides the electrophysiological basis for clinical rehabilitation. Ten patients with spasticity after stroke were selected to be estimated by modified Ashworth (MAS) assessment and a passive elbow sinusoidal motion experiment was carried out. At the same time, the sEMG of biceps and triceps were recorded. The results shows that the reflex electromyographic threshold could reflect the physiological mechanism of spasticity and had significant correlation with MAS scale which showed that sEMG could be prosperous for the clinical quantitative evaluation of spasticity of stroke patients.
Electromyography ; Humans ; Muscle Spasticity ; physiopathology ; Muscle, Skeletal ; physiopathology ; Stroke ; physiopathology

Acupuncture Therapy ; Humans ; Muscle, Skeletal ; physiopathology ; Spondylosis ; physiopathology ; therapy

This article summarizes relevant clinical studies on muscle status and osteoarthritis. Evidence from many researches have implied the importance of muscle weakness, decreased muscle strength and muscle function as pathological factor in the process of osteoarthritis, and muscle should also be an effective target for the treatment of osteoarthritis. Further study need to be conducted from the angle of muscle to explore the mechanism of osteoarthritis and to develop new drugs.
Humans ; Muscle Strength ; Muscle Weakness ; complications ; Muscle, Skeletal ; physiopathology ; Osteoarthritis ; etiology ; physiopathology

One of the most important and urgent issues in the field of space medicine is to reveal the potential mechanism underlying the disused muscle atrophy during the weightlessness or microgravity environment. It will conduce to find out effective methods for the prevention and treatment of muscle atrophy during a long-term space flight. Increasing data show that muscle spindle discharges are significantly altered following the hindlimb unloading, suggesting a vital role in the progress of muscle atrophy. In the last decades, we have made a series of studies on changes in the morphological structure and function of muscle spindle following simulated weightlessness. This review will discuss our main results and related researches for understanding of muscle spindle activities during microgravity environment, which may provide a theoretic basis for effective prevention and treatment of muscle atrophy induced by weightlessness.
Animals ; Hindlimb Suspension ; Muscle Spindles ; physiopathology ; Muscle, Skeletal ; physiopathology ; Muscular Atrophy ; physiopathology ; Space Flight ; Weightlessness Simulation

OBJECTIVE: To study the application of isokinetic muscle testing in identification of the faked paralysis to provide scientific data for establishing a standard system of muscle strength in forensic medicine identification. METHODS: Fifty-seven patients with bone fracture or nerve damage as damaged group and 128 normal subjects pretended paralysis as faked paralyzed group were included in this study. Isokinetic muscle testing was performed on bilateral knees of all subjects in the two groups. The peak torque (PT) and peak torque angle (PTA) were compared between both sides in each group. The features of torque-time graph of two groups were classified. RESULTS: In the damaged group, the differences of PT between two sides of flexors and extensors were statistically significant (P<0.05), while the dif- ferences of PTA were not statistically significant (P>0.05). In faked paralyzed group, the differences of PT and PTA between two sides of flexors and extensors were both statistically significant (P<0.05). The torque-time graph of damaged knee presented mostly as single lead peak, while torque-time graph of the faked paralyzed knee presented mostly as multiple peaks. CONCLUSION The feature of torque-time graph could be useful to identify the faked paralyzed extremities in forensic authentication.
Case-Control Studies ; Humans ; Knee Joint/physiopathology* ; Male ; Muscle Strength ; Muscle, Skeletal/physiopathology* ; Muscles ; Torque

EMG has been extensively used to study function of back muscle, which plays an important role in the objective assessment of occupational low back pain, yet the inherent large variability of EMG signals across subjects produced by reasons already known or unknown may mask true biological differences. Some useful parameters abstracted from 8-channel EMG signal in time-frequency domain are used or proposed and calculated in this paper to decrease this variability, when comparing the possible difference between low back pain patients and normal control group. The calculation of instantaneous median frequency is improved to decrease the interruption of background noise, and different power densities in EMG time-frequency spectrogram are observed in two tested groups.
Back ; Electromyography ; Fourier Analysis ; Humans ; Low Back Pain ; physiopathology ; Muscle, Skeletal ; physiopathology ; Spectrum Analysis

An automatic control system was designed to suppress pathological tremor on wrist joint with two degrees of freedom (DoF) using functional electrical stimulation (FES). The tremor occurring in the wrist flexion-extension and adduction-abduction was expected to be suppressed. A musculoskeletal model of wrist joint was developed to serve as the control plant, which covered four main muscles (extensor carpi radialis longus, extensor carpi ulnaris, flexor carpi radialis, and flexor carpi ulnaris). A second-order mechanical impedance model was used to describe the wrist skeletal dynamics. The core work was to design the controller and a hybrid control strategy was proposed, which combined inverse model based on feed forward control and linear quadratic regulator (LQR) optimal control. Performance of the system was tested under different input conditions (step signal, sinusoidal signal, and real data of a patient)., The results indicated that the proposed hybrid controller could attenuate over 94% of the tremor amplitude on multi-DoF wrist joint.
Electric Stimulation ; Humans ; Muscle, Skeletal ; physiopathology ; Tremor ; prevention & control ; therapy ; Wrist ; Wrist Joint ; physiopathology

To better analyze the problem of abnormal neuromuscular coupling related to motor dysfunction for stroke patients, the functional coupling of the multichannel electromyography (EMG) were studied and the difference between stroke patients and healthy subjects were further analyzed to explore the pathological mechanism of motor dysfunction after stroke. Firstly, the cross-frequency coherence (CFC) analysis and non-negative matrix factorization (NMF) were combined to construct a CFC-NMF model to study the linear coupling relationship in bands and the nonlinear coupling characteristics in different frequency ratios during elbow flexion and extension movement. Furthermore, the significant coherent area and sum of cross-frequency coherence were respectively calculated to quantitatively describe the intermuscular linear and nonlinear coupling characteristics. The results showed that the linear coupling relationship between multichannel muscles was different in frequency bands and the overall coupling was stronger in low frequency band. The linear coupling strength of the stroke patients was lower than that of the healthy subjects in different frequency bands especially in beta and gamma bands. For the nonlinear coupling, the intermuscular coupling strength of stroke patients in different frequency ratios was significantly lower than that of the healthy subjects, and the coupling strength in the frequency ratio 1∶2 was higher than that in the frequency ratio 1∶3. This method can provide a theoretical basis for exploring the intermuscular coupling mechanism of patients with motor dysfunction.
Case-Control Studies ; Electromyography ; Humans ; Muscle, Skeletal ; physiopathology ; Stroke ; physiopathology ; Stroke Rehabilitation

As the technologic sophistication of generation and distribution of electrical energy has grown, so has the general concern about the effects of electric fields on human health. There can be no doubt that the significance of electrical trauma will continue to grow with our increasing use of power. It is apparent that our understanding of the various forms of electric trauma must increase, while we continue to promote safety near electrical hazards and develop effective medical therapies. Tissue damage as a result of electrical injury occurs by two mechanisms which are summative in action and have a variable degree of contribute to the ultimate damage produced. Thermal tissue damage occurs as a result of heat generated within the tissue (which offer an electrical resistance) secondary to the passage of the electrical current. High temperatures can also lead to cell membrane components, e.g., phospholipids, to dissolve. Electroportation damage is the tissue damage induced secondary to the strong electric field. Transmembrane potentials caused by electrical current result in the formation of pore in the phospholipid component of the cell membrane resulting in loss of function of the cell membrane with consequent cell death.
Animals ; Electric Injuries/physiopathology* ; Heart Injuries/physiopathology* ; Hemodynamics ; Humans ; Muscle, Skeletal/injuries*

OBJECTIVETo study the effects of Tuina on muscular tension of flexor and extensor in patients with knee osteoarthritis (KOA).

METHODSFrom June 2009 to March 2010, 20 patients with KOA were observed, including 7 males and 13 females, the age ranged from 42 to 72 years with an average of 61 years. Eight patients were ailed with single knee, 12 patients were ailed with double knee. The maneuver of Tuina were Gun maneuvers (120 to 140 times per minute), An maneuvers, Na maneuvers and Ca maneuvers. The patients were treated 3 times every week,and 10 times were 1 course of treatment. The muscular tension of flexor and extensor were measured before and after treatment, and the press force of the point reached largest of L 500 g when the press was 500 g. The therapeutic effects were assessed by WOMAC (including pain, stiffness, functional activity and overall score) scale before and after treatment.

RESULTSThere was significant increase in the ill knee on L 500 g (P<0.01). There was significant decrease after treatment in WOMAC (P<0.01). There was significant positive correlation between the improvement rate of extensor and the improvement rate of therapeutic effects (P<0.01, r=0.764). There was significant positive correlation between the improvement rate of flexor and the improvement rate of therapeutic effects (P<0.01, r2=0.533).

CONCLUSIONTuina can improve muscular tension of flexor and extensor in patients with knee osteoarthritis, thus can improve the therapeutic effects.

Adult ; Aged ; Female ; Humans ; Male ; Manipulation, Orthopedic ; Middle Aged ; Muscle Tonus ; Muscle, Skeletal ; physiopathology ; Osteoarthritis, Knee ; physiopathology ; therapy