Lower limb joint kinematics in older adults during steady-state walking in the home setting

Older adults most commonly experience falls in the home setting, yet the extent to which age and the internal home environment influences gait remains poorly understood. This study aimed to measure lower limb joint kinematics in young and older adults when walking habitually throughout the home setting.

Ten healthy young adults (age: 27.7 ± 1.8 years) and ten older adults (age: 74.7 ± 7.0 years) performed nineteen diverse activities of daily living throughout a fully furnished single-bedroom apartment inclusive of a kitchen, bathroom, bedroom and living room. Each participant's lower limb joint kinematics and spatiotemporal gait parameters were measured using inertial measurement units, and their spatial location while ambulating throughout the apartment was captured using an ultra-wideband system.

Compared with young adults, older adults exhibited a smaller peak ankle flexion (p = 0.002, η²ₚ=0.52) and knee flexion (p = 0.040, η²ₚ=0.36) during walking throughout all living spaces. However, knee flexion in older adults was significantly greater than that of younger adults when walking in the bedroom through a narrow space beside a bed (mean difference: 8.0°, p < 0.001). Older age was significantly associated with slower walking speed (p = 0.006, η²ₚ=0.74), though walking speed was not found to vary significantly between living spaces (p > 0.05).

Lower limb joint motion during walking throughout the home setting is reduced in older adults compared to younger adults; however, the presence of spatial constraints imposed by the internal environment, including narrow walkways and obstacles such as beds, increases hip and knee motion demands in older adults compared to young adults. The findings of this study have implications for home interior design and fall risk assessment.