Proceedings of The Physiological Society

University College London December 2005 (2006) Proc Physiol Soc 1, C8

Oral Communications

Age-related changes in muscle response times and magnitudes in time-critical obstacle avoidance

Weerdesteyn, Vivian; Nienhuis, Bart; Dietz, Volker; Duysens, Jacques;

1. Sint Maartenskliniek Research, Development & Education, Nijmegen, Netherlands. 2. Spinal Cord Injury Center Balgrist, Zurich, Switzerland. 3. Rehabilitation Medicine, Radboud University Nijmegen Medical Centre, Nijmegen, Netherlands.


In daily life, independent and safe locomotion requires the ability to continuously adjust the locomotor pattern in response to environmental demands, like obstacles in the travel path. Adjustments of leg trajectories in response to an obstacle or target displacement can be as fast as 120 ms in young subjects (Weerdesteyn et al. 2004; Reynolds & Day, 2005). In obstacle avoidance under time pressure, elderly have been reported to be less successful (Chen et al. 1994). At the neuromuscular control level, however, it is not clear whether this is due to delayed onset latencies, reduced amplitudes, or both. In the present study, obstacle avoidance under time pressure was studied in 10 young (24.4

Where applicable, experiments conform with Society ethical requirements