Older Adults with Pre-sarcopenia/Sarcopenia have Increased Gastrocnemius Muscle Activity to Maintain Upright Postural Control at Stance Perturbation

Purpose With aging, there is a decline in the ability to balance, leading to a predisposition to falls. The study’s aim was to verify the influence of pre-sarcopenia/sarcopenia on the ability to recover postural stability during balance perturbation. Methods Fourteen older adults with pre-sarcopenia/sarcopenia (70.21 ± 2.80 years) and fourteen without sarcopenia (68.85 ± 3.50 years) were included. Sarcopenia was identified according to the European Consensus on Definition and Diagnosis (EWGSOP) criteria. Ten balance perturbations were applied. Variables Analyzed: Latency for the peak of center of pressure (CoP), CoP velocity, latency time and electromyographic (EMG) amplitude. Results There was a difference between groups in the latency for the peak of CoP ( p = 0.041), velocity of CoP ( p = 0.016) and EMG amplitude of the lateral gastrocnemius ( p = 0.019). There was difference in perturbations within pre-sarcopenic/sarcopenic group on latency for the peak of CoP in perturbations 1 and 2 ( p = 0.023) and 1 and 10 ( p = 0.041). There was a significant difference on velocity of CoP in non-sarcopenic group in comparison 1 and 2 ( p = 0.040) perturbations. Conclusion Older adults with pre-sarcopenia/sarcopenia require greater ankle plantarflexor activation to remain standing in response to perturbation compared to older adults without sarcopenia. In repetitive perturbations, the adaptations of pre-sarcopenic/sarcopenic group increase the magnitude of the EMG signal.