A.H. Vrieling a,*, H.G. van Keeken b, T. Schoppen c, E. Otten b, A.L. Hof a,b, J.P.K. Halbertsma a, K. Postema a
Received 11 June 2007; received in revised form 26 November 2007; accepted 2 December 2007

Objective: To study balance control on a moving platform in lower limb amputees.
Design: Observational cohort study.
Participants: Unilateral transfemoral and transtibial amputees and able-bodied control subjects.
Interventions: Balance control on a platform that moved in the anteroposterior direction was tested with eyes open, blindfolded and while
performing a dual task.
Main outcome measures: Weight bearing symmetry, anteroposterior ground reaction force and centre of pressure shift.
Results: Compared to able-bodied subjects, in amputees the anteroposterior ground reaction force was larger in the prosthetic and nonaffected
limb, and the centre of pressure displacement was increased in the non-affected limb and decreased in the prosthetic limb. In
amputees body weight was loaded more on the non-affected limb. Blindfolding or adding a dual task did not influence the outcome measures
Conclusion: The results of this study indicate that experienced unilateral amputees with a high activity level compensate for the loss of ankle
strategy by increasing movements and loading in the non-affected limb. The ability to cope with balance perturbations is limited in the
prosthetic limb. To enable amputees to manage all possible balance disturbances in real life in a safe manner, we recommend to improve
muscle strength and control in the non-affected limb and to train complex balance tasks in challenging environments during rehabilitation.

# 2007 Elsevier B.V. All rights reserved.

a Center for Rehabilitation, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
b Center for Human Movement Sciences, University of Groningen, Groningen, The Netherlands
c Tjongerschans Hospital, Heerenveen, The Netherlands