Less hip joint loading only during running rather than walking in elderly compared to young adults

Area of Science:

• Biomechanics
• Gerontology
• Orthopedics

Background:

• Weight-bearing exercises like walking and running can increase hip bone mass in postmenopausal women.
• Optimal exercise speeds for bone growth (osteogenesis) are debated due to poorly understood loading patterns.
• Age-related gait changes can alter hip loading, making findings from young populations unreliable for the elderly.

Purpose of the Study:

• To quantify and compare peak hip contact forces (HCFs) during walking and running at various speeds in young and elderly women.
• To investigate age-related differences in gait kinematics and kinetics influencing hip loading.
• To identify gait parameters that predict hip loading during different locomotion modes.

Main Methods:

• Integrated 3D motion capture and musculoskeletal modeling were used to calculate peak HCFs.
• Fourteen young (21.4±1.6 years) and 14 elderly (69.8±3.4 years) female participants walked and ran at speeds from 3 to 9 km/h.
• Hip joint moments and kinematics were analyzed in relation to HCFs.

Main Results:

• Peak HCFs were similar during walking across age groups.
• Elderly women exhibited lower peak HCFs during running than young women, attributed to reduced stride length and hip adduction.
• Hip adduction moment predicted peak HCF during impact for both walking and running. Hip extension and external rotation moments predicted secondary peak HCFs in elderly and young individuals, respectively.

Conclusions:

• Running does not impose additional hip loading compared to walking in elderly women at similar speeds, unlike in young women.
• Differences in gait mechanics lead to reduced hip loading during running in elderly women.
• Findings provide crucial insights for designing targeted exercise interventions to prevent hip bone loss in postmenopausal women.