Comparison in three dimensional gait kinematics between young and older adults on land and in shallow water

This study investigated in three-dimensional space, firstly whether the aquatic medium and secondly ageing, had any effect on the lower limb's joint angles during aquatic-based gait. Three-dimensional joint kinematics of the lower limb of 51 healthy male participants [25 young group (24.6 +/- 4.9 years, 172.1 +/- 5.5 cm, 69.8 +/- 10.3 kg) and 26 older group (58.5 +/- 5.1 years, 167.9 +/- 5.1 cm, 70.8 +/- 12.1 kg)] were quantified during land and shallow water walking. Participants walked at their self-selected comfortable speed in both mediums. The results suggested that the properties of water hydrodynamic drag, and buoyancy affected the gait kinematics for both groups. Both age groups used more of their hip flexion in the aquatic environment to help them propel forward instead of using the ankle plantarflexion. The effect of age during the aquatic-based gait was identified in ankle adduction angle and knee abduction/adduction angle at initial contact. Only the older group elicited a significantly smaller ankle adduction angle during the aquatic-based gait when compared to the land-based gait. Only the young group elicited a significantly larger knee abduction/adduction angle at initial contact during the aquatic-based gait when compared to the land-based gait. These findings can facilitate professionals in the area of aquatic rehabilitation to better customise aquatic-based walking exercise programmes to suit their client's specific needs.