Related Experiment Video
Updated: Jan 28, 2026

Evaluating Postural Control and Lower-extremity Muscle Activation in Individuals with Chronic Ankle Instability
Published on: September 18, 2020
Older and young adults adopt different postural strategies during quiet bipedal stance after ankle plantarflexor
Sébastien Boyas1, Emily R Medd2, Sébastien Beaulieu3
1Le Mans University, MIP, EA, 4334, Laboratory "Movement, Interactions, Performance", Faculty of Sciences and Technologies, Department of Sport Sciences, Le Mans, France; Bruyère Research Institute, Aging and Movement Research Laboratory, 43 Bruyère Street, Ottawa, ON K1N 5C8, Canada; University of Ottawa, Faculty of Health Sciences, School of Human Kinetics, 125 University Avenue, Ottawa, ON K1N 6N5, Canada.
Background:
The individual effects of fatigue and age on postural control have been extensively studied. However, there is a lack of knowledge about the combined effects of fatigue and age on postural control and posture.
Research Question:
The purpose of this study was to investigate the influence of age and muscle fatigue on bipedal stance postural control and posture.
Methods:
Twenty-three participants, fourteen young adults and nine older adults performed 30-s bipedal postural trials before and after fatigue. The fatigue protocol consisted in repeating heel raises until exhaustion. Back, hip, knee and ankle joint angles and centre of pressure (COP) displacements were recorded with a 3D motion capture system and a force plate.
Results:
Fatigue induced similar increases in sway area and COP velocity for both populations. This was associated with a forward displacement of the COP position for both populations but with different postural adaptations. Similar increased flexions (+1.7 to 1.8°) for all joint angles (ankle, knee, hip and back) joints were observed after fatigue for older adults, whereas young adults mainly showed increased flexion for the ankle joint (+3.1°) and decreased flexion at the hip (-1.2°).
Significance:
It can be argued that older adults act on all joints because they are too weak to sufficiently modify any joint individually, contrary to young adults. These posture adaptations may be strategies to cope with fatigue by limiting the reliance on fatigued plantarflexors, increasing ankle stiffness, increasing the sensitivity of muscle spindles, increasing the number of degrees of freedom of the task.
Related Concept Videos
Ankle Joint
Fatigue
Muscle Recovery and Fatigue
Fatigue Strength of Concrete
Adult Stem Cells
Persuasion Strategies

