Increased double stance may be needed on uneven terrain or with impaired balance so that step length is sacrificed for stability. Elderly persons with a fear of falling increase their double stance time. Double stance time is a strong predictor of gait velocity and step length. Unless elderly persons have diseases such as osteoporosis with kyphosis, they walk upright, with no forward lean. Foot clearance in swing is the same in elderly as in younger persons.
Joint motion changes with age.
The overall motion of the knee is unchanged. Hip motion is unchanged in the sagittal plane but in the frontal plane shows greater adduction. Pelvic motion is reduced in the frontal and transverse planes, and transverse plane rotation is reduced. Step length is shorter in the elderly. One explanation is that calf muscles are weak and cannot produce sufficient plantar flexion.