Differences of muscle co-contraction of the ankle joint between young and elderly adults during dynamic postural control at different speeds

Abstract

BackgroundAgonist and antagonist muscle co-contractions during motor tasks are greater in the elderly than in young adults. During normal walking, muscle co-contraction increases with gait speed in young adults, but not in elderly adults. However, no study has compared the effects of speed on muscle co-contraction of the ankle joint during dynamic postural control in young and elderly adults. We compared muscle co-contractions of the ankle joint between young and elderly subjects during a functional stability boundary test at different speeds.MethodsFifteen young adults and 16 community-dwelling elderly adults participated in this study. The task was functional stability boundary tests at different speeds (preferred and fast). Electromyographic evaluations of the tibialis anterior and soleus were recorded. The muscle co-contraction was evaluated using the co-contraction index (CI).ResultsThere were no statistically significant differences in the postural sway parameters between the two age groups. Elderly subjects showed larger CI in both speed conditions than did the young subjects. CI was higher in the fast speed condition than in the preferred speed condition in the young subjects, but there was no difference in the elderly subjects. Moreover, after dividing the analytical range into phases (acceleration and deceleration phases), the CI was larger in the deceleration phase than in the acceleration phase in both groups, except for the young subjects in the fast speed conditions.ConclusionsOur results showed a greater muscle co-contraction of the ankle joint during dynamic postural control in elderly subjects than in young subjects not only in the preferred speed condition but also in the fast speed condition. In addition, the young subjects showed increased muscle co-contraction in the fast speed condition compared with that in the preferred speed condition; however, the elderly subjects showed no significant difference in muscle co-contraction between the two speed conditions. This indicates that fast movements cause different influences on dynamic postural control in elderly people, particularly from the point of view of muscle activation. These findings highlight the differences in the speed effects on muscle co-contraction of the ankle joint during dynamic postural control between the two age groups.

Reliability and validity of rehabilitative ultrasound images obtained using a hands-free fixed probe in measuring the muscle structures of the tibialis anterior and the gastrocnemius

“…Excessive muscle co-contraction between the tibialis anterior (TA) and the gastrocnemius (GCM) causes stiffness in the ankle joint and limits postural control [1]. The TA provides a peripheral feedback mechanism modulating agonists such as the GCM in maintaining human upright posture and activates reciprocal inhibition that is more likely to be effective for ankle strategy [2].…”

Muscle co-contraction in elderly people change due to postural stability during single-leg standing

“…To evaluate the relative level of co-contraction of the TA and SOL muscles, the co-contraction index (CI) was calculated using the method described by Falconer and Winter [ 22 ]. We introduced the detailed explanation in our previous study [ 23 ]. We used following equations: where I ant is the total antagonistic activity, calculated with the following Eq.…”

Correction to: Differences of muscle co-contraction of the ankle joint between young and elderly adults during dynamic postural control at different speeds

“…After the publication of this work [ 1 ] an error was noticed in Table 3. In the column ‘Elderly’, in the last row it states 98 ± 11.87** however the correct value should be: 34.98 ± 11.87**.…”