OBJECTIVE To investigate muscle activities during locking-unlocking movements. METHODS Thirty right-handed healthy volunteers, aged between 18-23 years, without any orthopedic or neurological disorders participated in the study. We choose the clavicular part of the deltoid muscle, biceps brachii, pronator teres, extensor digitorum, pronator quadratus, first dorsal interosseous muscles and mus...

Oscillatory activity in the primate motor cortex has been shown to be phase locked to oscillations in contralateral hand and forearm muscle activity in the 15-30 Hz frequency range. Recent studies have shown that the degree of coupling between the cortex and the periphery is strongly influenced by the type and degree of movements of the digits. It has also been suggested that changes in cortico...

BACKGROUND Long-term piano training might induce some biochemical and structural adaptations in the intrinsic muscles of the hand or change the motor strategy of the nervous system. The main purpose of this study was to analyze whether the intrinsic muscles of the hands of pianists and sedentary controls differ in electromyographic characteristics at different strengths. METHODS Fifteen colle...

The split hand phenomenon refers to predominant wasting of thenar muscles and is an early and specific feature of amyotrophic lateral sclerosis (ALS). A novel split hand index (SI) was developed to quantify the split hand phenomenon, and its diagnostic utility was assessed in ALS patients. The split hand index was derived by dividing the product of the compound muscle action potential (CMAP) am...

During demanding voluntary contractions (e.g., high force or fatigue), activation is not restricted to the target muscle but extends to other ipsilateral muscles; even contralateral muscles become activated. The contralateral "irradiation" of activity was measured in five subjects during submaximal and maximal voluntary contractions (MVCs) of the first dorsal interosseous (FDI) (index finger ab...

Partial weight support may hold promise as a therapeutic adjuvant during rehabilitation after stroke by providing a permissive environment for reducing the expression of abnormal muscle synergies that cause upper limb impairment. We explored the neurophysiological effects of upper limb weight support in 13 healthy young adults by measuring motor-evoked potentials (MEPs) from transcranial magnet...

OBJECTIVE Changes in cortical excitability during motor imagery were investigated in order to reveal the effect of hand dominance. During motor imagery, motor evoked potentials (MEPs) were recorded from the first dorsal interosseous (FDI) muscle of the dominant hand using transcranial magnetic stimulation (TMS). METHODS Twelve healthy right-handed subjects participated. Three motor imagery ta...

1. The electrical activity of up to eight concurrently active motor units has been recorded from the human deltoid and first dorsal interosseous (f.d.i.) muscles. The detected myoelectric signals have been decomposed into their constituent motor-unit action potential trains using a recently developed technique.2. Concurrently active motor unit behaviour has been examined during triangular force...