Muscle temperature has a different effect on force fluctuations in young and older women

Authors: Dewhurst, S., Graven-Nielsen, T., De Vito, G. and Farina, D.

Journal: Clinical Neurophysiology

Volume: 118

Issue: 4

Pages: 762-769

ISSN: 1388-2457

DOI: 10.1016/j.clinph.2006.12.006

Abstract:

Objective: To investigate the effect of muscle temperature on force fluctuations during isometric contractions in young and older females. Methods: Fifteen young and 11 older subjects performed 3 × 30-s long submaximal isometric ankle dorsi-flexions (5%, 10%, and 15% of the maximal force). Tibialis anterior muscle temperature was monitored with an intramuscular probe and manipulated to obtain a cold, control, and warm condition. The coefficient of variation (CofV) and the relative power in the frequency bands 0-3 Hz (low), 4-6 Hz (middle), and 8-12 Hz (high) of the force signal were computed to characterise steadiness. Intramuscular EMG signals were recorded from the tibialis anterior muscle to assess motor unit discharge pattern. Results: CofV was higher in the older than in the young subjects (P < 0.001) in all conditions. In the older group only, CofV increased with cooling with respect to control temperature (P < 0.001), whereas in the young group only, relative power of force fluctuations at high frequency decreased with cooling. Motor unit discharge rate and inter-pulse interval variability were not different between groups and across temperatures. Conclusions: The findings indicate a different effect of temperature on the ability to maintain constant force in young and older subjects. Significance: These results highlight the risk of further impairment to the motor control of older individuals with varying temperature. © 2006 International Federation of Clinical Neurophysiology.

Source: Scopus

Muscle temperature has a different effect on force fluctuations in young and older women.

Authors: Dewhurst, S., Graven-Nielsen, T., De Vito, G. and Farina, D.

Journal: Clin Neurophysiol

Volume: 118

Issue: 4

Pages: 762-769

ISSN: 1388-2457

DOI: 10.1016/j.clinph.2006.12.006

Abstract:

OBJECTIVE: To investigate the effect of muscle temperature on force fluctuations during isometric contractions in young and older females. METHODS: Fifteen young and 11 older subjects performed 3x30-s long submaximal isometric ankle dorsi-flexions (5%, 10%, and 15% of the maximal force). Tibialis anterior muscle temperature was monitored with an intramuscular probe and manipulated to obtain a cold, control, and warm condition. The coefficient of variation (CofV) and the relative power in the frequency bands 0-3Hz (low), 4-6Hz (middle), and 8-12Hz (high) of the force signal were computed to characterise steadiness. Intramuscular EMG signals were recorded from the tibialis anterior muscle to assess motor unit discharge pattern. RESULTS: CofV was higher in the older than in the young subjects (P<0.001) in all conditions. In the older group only, CofV increased with cooling with respect to control temperature (P<0.001), whereas in the young group only, relative power of force fluctuations at high frequency decreased with cooling. Motor unit discharge rate and inter-pulse interval variability were not different between groups and across temperatures. CONCLUSIONS: The findings indicate a different effect of temperature on the ability to maintain constant force in young and older subjects. SIGNIFICANCE: These results highlight the risk of further impairment to the motor control of older individuals with varying temperature.

Source: PubMed

Muscle temperature has a different effect on force fluctuations in young and older women

Authors: Dewhurst, S., Graven-Nielsen, T., De Vito, G. and Farina, D.

Journal: CLINICAL NEUROPHYSIOLOGY

Volume: 118

Issue: 4

Pages: 762-769

eISSN: 1872-8952

ISSN: 1388-2457

DOI: 10.1016/j.clinph.2006.12.006

Source: Web of Science (Lite)

Muscle temperature has a different effect on force fluctuations in young and older women.

Authors: Dewhurst, S., Graven-Nielsen, T., De Vito, G. and Farina, D.

Journal: Clinical Neurophysiology

Volume: 118

Issue: 4

Pages: 762-769

Publisher: Elsevier BV

ISSN: 1388-2457

DOI: 10.1016/j.clinph.2006.12.006

Abstract:

OBJECTIVE: To investigate the effect of muscle temperature on force fluctuations during isometric contractions in young and older females.

METHODS: Fifteen young and 11 older subjects performed 3x30-s long submaximal isometric ankle dorsi-flexions (5%, 10%, and 15% of the maximal force). Tibialis anterior muscle temperature was monitored with an intramuscular probe and manipulated to obtain a cold, control, and warm condition. The coefficient of variation (CofV) and the relative power in the frequency bands 0-3Hz (low), 4-6Hz (middle), and 8-12Hz (high) of the force signal were computed to characterise steadiness. Intramuscular EMG signals were recorded from the tibialis anterior muscle to assess motor unit discharge pattern.

RESULTS: CofV was higher in the older than in the young subjects (P<0.001) in all conditions. In the older group only, CofV increased with cooling with respect to control temperature (P<0.001), whereas in the young group only, relative power of force fluctuations at high frequency decreased with cooling. Motor unit discharge rate and inter-pulse interval variability were not different between groups and across temperatures.

CONCLUSIONS: The findings indicate a different effect of temperature on the ability to maintain constant force in young and older subjects.

SIGNIFICANCE: These results highlight the risk of further impairment to the motor control of older individuals with varying temperature.

Source: Manual

Muscle temperature has a different effect on force fluctuations in young and older women.

Authors: Dewhurst, S., Graven-Nielsen, T., De Vito, G. and Farina, D.

Journal: Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology

Volume: 118

Issue: 4

Pages: 762-769

eISSN: 1872-8952

ISSN: 1388-2457

DOI: 10.1016/j.clinph.2006.12.006

Abstract:

Objective

To investigate the effect of muscle temperature on force fluctuations during isometric contractions in young and older females.

Methods

Fifteen young and 11 older subjects performed 3x30-s long submaximal isometric ankle dorsi-flexions (5%, 10%, and 15% of the maximal force). Tibialis anterior muscle temperature was monitored with an intramuscular probe and manipulated to obtain a cold, control, and warm condition. The coefficient of variation (CofV) and the relative power in the frequency bands 0-3Hz (low), 4-6Hz (middle), and 8-12Hz (high) of the force signal were computed to characterise steadiness. Intramuscular EMG signals were recorded from the tibialis anterior muscle to assess motor unit discharge pattern.

Results

CofV was higher in the older than in the young subjects (P<0.001) in all conditions. In the older group only, CofV increased with cooling with respect to control temperature (P<0.001), whereas in the young group only, relative power of force fluctuations at high frequency decreased with cooling. Motor unit discharge rate and inter-pulse interval variability were not different between groups and across temperatures.

Conclusions

The findings indicate a different effect of temperature on the ability to maintain constant force in young and older subjects.

Significance

These results highlight the risk of further impairment to the motor control of older individuals with varying temperature.

Source: Europe PubMed Central