Leg and trunk muscle coordination and postural sway during increasingly difficult standing balance tasks in young and older adults. (September 2016)

• Record Type: Journal Article
• Authors: Donath, Lars; Kurz, Eduard; Roth, Ralf; Zahner, Lukas; Faude, Oliver
• Is Part Of: Maturitas. Volume 91(2016)
• Page Start: 60
• Page End: 68
• Publication Date: 2016-09
• Subjects: Elderly -- Static balance -- Co-contraction -- Amplitude ratios -- Co-activation -- Neuromuscular training -- Balance training -- Aging -- Postural control; Climacteric -- Periodicals; Menopause -- Periodicals; Climacteric -- Periodicals; Geriatrics -- Periodicals; Menopause -- Periodicals; Middle Aged -- Periodicals; Climatère -- Périodiques; Ménopause -- Périodiques; Climacterium; Climacteric; Menopause; Electronic journals; Periodicals; 612.66
• DOI: 10.1016/j.maturitas.2016.05.010
• Languages: English
• ISSNs: 0378-5122

Abstract

Highlights: Older adults had higher electrophysiological costs than young adults for given balance tasks. Older adults showed more relative muscle activity of the tibialis muscle than did young adults. Young adults had a higher contribution from internal oblique coordination at the expense of the multifidus contribution. Older adults showed inverse muscle activity coordination patterns at the ankle and trunk on all stance conditions. Co-activation was higher in older adults for the ankle and higher in young adults for the trunk. Abstract: Ageing impairs body balance and increases older adults' fall risk. Balance training can improve intrinsic fall risk factors. However, age comparisons of muscle activity responses during balance tasks are lacking. This study investigated relative muscle activity, muscle coordination and postural sway during various recommended static balance training tasks. Muscle activity (%MVC), amplitude ratios (AR) and co-activity (CAI) were determined during standing tasks for 30 s (1: double limb stance on a foam surface, eyes open; 2: double limb stance on firm ground, eyes closed; 3: double limb stance, feet in step position on a foam surface, eyes open; 4: double limb stance, feet in step position on firm ground, eyes closed; 5: single limb stance on firm ground, eyes open) in 20 healthy young adults (24 ± 2 y) and 20 older adults (73 ± 6 y). Surface electromyography (SEMG) was applied (SENIAM guidelines) to ankle (tibialis anterior, soleus, medial gastrocnemius, peroneus longus) and thigh (vastus lateralis, vastus medialis, biceps femoris, semitendinosus) muscles (non-dominant leg). Electrodes over trunk (multifidus and internal oblique) muscles were applied bilaterally. Two- to six-fold higher levels of relative muscle activity were found in older adults for ankle (0.0002 < p < 0.001), thigh (0.0008 < p < 0.075) and trunk (0.001 < p < 0.036) muscles. Co-activation was elevated in young adults for the trunk (0.001 < p < 0.031) and in older adults for the ankle (0.009 < p < 0.03). Age-group differences were observed for muscle coordination patterns during all stance conditions at the ankle (0.06 < ηp 2 < 0.28) and the trunk (0.14 < ηp 2 < 0.23). Older adults had higher electrophysiological costs for all stance conditions. Muscle coordination showed inverse activity patterns at the ankle and trunk. Optimal balance and strength training programs should take into account age-specific alterations in muscle activity.