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Grevendonk, L.

Publications and source records attributed to Grevendonk, L..

2 recordsLinked to original sources

Type II muscle fibre properties are not associated with balance recovery following large perturbations during walking in young and older adults

Falls among older adults are often attributed to declining muscle strength with ageing. Associations between muscle strength and balance control have been reported, but the evidence for, and key mechanisms of resistance exercise in fall prevention are unclear. No studies have directly examined the relationship between muscle fibre characteristics and reactive balance control. Here, we address whether or not Type II muscle fibre characteristics associate with reactive balance during walking in young and older adults with varying muscle fibre type composition. We analyse muscle biopsy-derived fibre characteristics and stability during a treadmill-based walking perturbation (trip-like) task of healthy young adults, healthy, normally active older adults, trained older adults and physically impaired older adults. We find no significant associations between Type II muscle fibre properties and reactive balance during walking, indicating that practitioners and researchers should consider more than just the muscle tissue properties when assessing and intervening on fall risk.

physiology↗

Older adults demonstrate interlimb transfer of reactive gait adaptations to repeated unexpected gait perturbations

The ability to rapidly adjust gait to cope with unexpected mechanical perturbations declines with ageing. Previous studies however, have not ensured that pre-perturbation gait stability was equivalent, meaning that differences in unperturbed gait stability may have influenced the outcomes, which this study addresses. We also examine if interlimb transfer of gait adaptations are observed in healthy older adults, potentially driven by the increased motor error experienced due to their reduced ability to cope with the perturbations. 30 young and 28 older healthy adults experienced ten unpredictable treadmill belt accelerations (the first and last applied to the right leg, the others to the left) during walking at their stability-normalised walking speeds (young: 1.32{+/-}0.07m/s; older: 1.31{+/-}0.13m/s). Using kinematic data, we assessed the margins of stability during unperturbed walking and the first eight post-perturbation recovery steps. Older adults required three more steps to recover during the first perturbation to each leg than the young adults. Yet, after repeated perturbations of the left leg, older adults required only one more step to recover. Interestingly, for the untrained right leg, we found an improvement of three steps in the recovery of the older adults, indicating interlimb transfer of the improvements. Age differences in reactive gait stability remain even when participants walk with equivalent stability. Furthermore, we show that healthy older adults can transfer improvements in balance recovery made during repeated perturbations to one limb to their recovery following a perturbation to the untrained limb.

neuroscience↗