Introduction: Clinical measurements of strength in stroke subjects are usually performed and portable dynamometers are one of the most employed instruments. Objective: To verify the standardization procedures of the methods used to assess the strength of the trunk and upper limb muscles with portable dynamometers in stroke subjects, as well as to assess the psychometric properties which were al...

Essential tremor is characterized by persistent, usually bilateral and symmetric, postural or kinetic activation of agonist and antagonist muscles involving either the distal or proximal upper extremity. Quality of life is often affected and one's ability to perform daily tasks becomes impaired. Oral therapies, including propranolol and primidone, can be effective in the management of essential...

We sought to establish whether spastic hypertonia results from changes in intrinsic muscle properties or from altered stretch reflex properties. We hypothesized that finger flexor spastic hypertonia is primarily of neural origin, and that the dynamics of spastic muscle responses to stretch should therefore reflect the dynamics of muscle spindle receptor responses. In 12 stroke survivors, we rec...

The purpose of this study was to determine whether the maximum shortening velocity (Vmax) in Hill's mechanical model (A. V. Hill. Proc. R. Soc. London Ser. B. 126: 136-195, 1938) should be scaled with activation, measured as a fraction of the maximum isometric force (Fmax). By using the quick-release method, force-velocity (F-V) relationships of the wrist flexors were gathered at five different...

Stimulus-triggered averaging (StTA) of electromyographic (EMG) activity from 24 simultaneously recorded forelimb muscles was used to investigate properties of primary motor cortex (M1) output in the macaque monkey. Two monkeys were trained to perform a reach-to-grasp task requiring multijoint coordination of the forelimb. EMG activity was recorded from 24 forelimb muscles including 5 shoulder, ...

BACKGROUND Impaired hand function is common in patients with arthritis and it affects performance of daily activities; thus, hand exercises are recommended. There is little information on the extent to which the disease affects activation of the flexor and extensor muscles during these hand-dexterity tasks. The purpose of this study was to compare muscle activation during such tasks in subjects...

In this paper, a calibration method to compensate for changes in SEMG amplitude with joint angle is introduced. Calibration factors were derived from constant amplitude surface electromyogram (SEMG) recordings from the biceps brachii (during elbow flexion) and the triceps brachii (during elbow extension) across seven elbow joint angles. SEMG data were then recorded from the elbow flexors (bicep...

BACKGROUND Recently, the number of elderly individuals who participate in sports has increased, thus injuries from overuse are now becoming recognized in the elderly population. Therefore, it is important to determine which muscle groups and tendons are most affected with aging to plan appropriate exercise interventions for elderly individuals. In particular, muscles and tendons in knee extenso...

OBJECTIVE The aim of this study was to analyze the effects of aging on the degree of thoracic kyphosis and peak torque of the trunk flexor and extensor muscles among women without a densitometric diagnosis of osteoporosis. METHODS Thirty women were selected to make up three groups: young women (n = 10; 24.60 ± 2.27 years of age); adults (n = 10; 43.50 ± 2.88); and elderly women (n = 10; 62.40...

The aim of the study was to quantify the workload on the upper extremity for fundamental work tasks during machine milking. Eleven milkers working in a loose-housing system with a milking parlour participated in the study. Muscle activity for the biceps and the forearm flexors, as well as positions and movements of the wrists were simultaneously measured by electromyography and electrogoniometr...