Age-associated changes in lower limb weight-bearing strategy during walking

Area of Science:

• Biomechanics
• Gerontology
• Human Movement Science

Background:

• Aging causes a shift in joint moment generation from the ankle and knee towards the hip during locomotion.
• This age-related redistribution is well-documented for propulsion but less understood for weight-bearing.
• Sagittal plane moments are studied more than frontal plane moments, despite their contribution to vertical support.

Purpose of the Study:

• To investigate how aging affects the contributions of sagittal and frontal plane joint moments to weight-bearing.
• To examine these effects across different walking speeds.

Main Methods:

• Gait analysis was conducted on young and older adults walking at preferred and faster speeds.
• Stepwise linear regression was used to identify joint moments predicting vertical ground reaction force (VGRF).
• 24 young and 17 healthy older adults participated.

Main Results:

• Young adults primarily used hip abduction and knee extension moments for leading limb weight-bearing.
• Older adults relied on hip extension for leading limb weight-bearing and hip flexion for trailing limb weight-bearing.
• Changes in knee extension moments influenced trailing limb weight-bearing in young adults, while hip extension moments did in older adults.

Conclusions:

• Older and younger adults exhibit distinct joint moment strategies for generating vertical support forces during walking.
• These differences are evident in both leading and trailing limb support and vary with walking speed.