Motor-unit coherence during isometric contractions is greater in a hand muscle of older adults.

Greater in a Hand Muscle of Older Adults Motor-Unit Coherence During Isometric Contractions Is

Motor unit discharge rate during submaximal isometric contractions in young and older adults following resistance exercise

In previous investigations, we have demonstrated that: 1) motor unit discharge rate during maximal voluntary effort is greater in young adults than in older persons, though motor unit discharge rate at 50% of maximal effort is similar in these two groups (Kamen et al., 1995), 2) motor unit discharge rates at submaximal forces declines as a result of resistance exercise training in young and old...

Steadiness is reduced and motor unit discharge is more variable in old adults.

The purpose of this study was to compare the steadiness and discharge rate of motor units during submaximal contractions performed by young and old adults. Subjects performed isometric and slow shortening and lengthening contractions with the first dorsal interosseous muscle. The steadiness of the isometric and slow anisometric contractions was less for the old subjects compared with young subj...

Rate coding is compressed but variability is unaltered for motor units in a hand muscle of old adults.

The discharge of single motor units (n = 34) in the first dorsal interosseus muscle and the fluctuations in force during steady contractions were measured across a range of index finger abduction forces in old adults (77.1 +/- 6.9 yr, n = 20). These results were compared with previously reported data on 38 motor units from young adults (25.7 +/- 5.7 yr). Both minimal and peak discharge rates in...

Age-related decline in rate of torque development is accompanied by lower maximal motor unit discharge frequency during fast contractions.

The aim of this study was to investigate the association between the rate of torque development and maximal motor unit discharge frequency in young and elderly adults as they performed rapid submaximal contractions with the ankle dorsiflexors. Recordings were obtained of the torque exerted by the dorsiflexors during the isometric contractions and the surface and intramuscular electromyograms (E...