Hips and ankles are key
This study investigated how ‘postural sway’ (a componenet of balance) is affected in people with HSP. It looked at 2 very specific components of balance – hip abduction strength and stiffness at the ankle. The study compared 20 HSPers with 18 non-HSPers.
They found that the HSPers had:
* higher sway in both sideways and forward/backward directions
* reduced strength at hips and ankles
* greater ankle stiffness
* and forward/backward sway was less in those whose ankles were more stiff.
Possible implications for HSPers:
Strengthen hip abductors to improve stability.
If hip abductors are weak, take extra caution to prevent falls.
Ankle stiffness was seen to reduce sway and may therefore improve stability – so don’t overstretch the ankle.
To determine how postural sway is affected in people with spastic paraparesis (pwSP) and the impact of different impairments.
In 20 pwSP and 18 matched healthy controls, standing postural sway was measured with eyes open and closed. Vibration threshold, isometric ankle and hip muscle strength and ankle stiffness with the participant at rest or pre-activating the muscle was measured.
Antero-posterior (AP) and medio-lateral (ML) sway was higher in pwSP. Muscle strength was reduced and ankle stiffness increased in pwSP. Increased vibratory threshold was seen in 35% of participants. Higher total ankle stiffness (R2=0.44) was associated with lower AP sway with eyes open whilst hip abductor weakness was associated with increased ML sway with eyes open (R2=0.36) or closed (R2=0.47) or AP sway with the eyes closed (R2=0.48).
The degree of postural sway was related to muscle paresis of the hip abductors particularly in the ML direction and under conditions of reduced sensory input. People with higher total ankle stiffness have less AP sway suggesting that this may help to stabilise the body.
SOURCE: Gait Posture. 2013 Apr 12. pii: S0966-6362(13)00137-9. doi: 10.1016/j.gaitpost.2013.03.001. [Epub ahead of print]
Balance dysfunction in hereditary and spontaneous spastic paraparesis.
School of Health Professions, Peninsula Allied Health Centre, University of Plymouth, Derriford Road, Plymouth PL6 8BH, United Kingdom.
Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.