Garling EH et al. – Rehabilitation programs for RA patients should include besides muscle strength training, elements of muscle-coordination training. Methods
Hypthesis that RA pts with a total knee prosthesis (MB) will show more co-contraction to stabilize the knee joint during a step-up task vs those with a fixed bearing total knee prosthesis (FB) was tested
Surface EMG, kinematics and kinetics about the knee were recorded during a step-up task of a MB group (n=5), a FB group (n=4) and a control group (n=8)
Surface EMG levels of thigh muscles were calibrated to either knee flexion or extension moments by means of isokinetic contractions on a dynamometer
During the step-up task co-contraction indices were determined from an EMG-force model
Results
Controls showed a higher active ROM during the step-up task vs patient group
In the control group higher average muscle extension, flexion and net moments during single limb support phase were observed vs patient group
During the 20–60% interval of the single limb support, MB pts showed a higher level of flexor activity, resulting in a lower net joint moment, however co-contraction levels were not different
Arthroplasty pts showed a 40% higher level of co-contraction during this interval vs controls
Control subjects used higher extension moments, resulting in a higher net joint moment
Visual analysis revealed a timing difference between the MB and FB group
The FB group seems to co-contract approximately 20% later compared to the MB group
RA pts after total knee arthroplasty show a lower net knee joint moment and a higher co-contraction than controls indicating avoidance of net joint load and an active stabilization of the knee joint
MB and FB pts showed no difference in co-contraction levels, although timing in FB was closer to controls than MB subjects
See all
