Luke Perraton – Abstract

P15  Quadriceps rate of force development following total knee replacement is associated with gait speed – low-cost clinically feasible methodology

Perraton LG[1], Bower KJ[2], Mentiplay BF[3], Feller J[4], Whitehead T[4], Webster K[3], Clark R[2]

  1. Department of Physiotherapy, Monash University, Melbourne, Australia
  2. School of Health and Sports Sciences, University of the Sunshine Coast, Sippy Downs, Australia
  3. Faculty of Health Sciences, La Trobe University, Melbourne, Australia
  4. Orthosport Victoria, Epworth Hospital, Melbourne, Australia

Background: Rate of force development (RFD) is a measure of how rapidly a muscle can produce force. Insufficient quadriceps strength and RFD following total knee replacement (TKR) may be associated with reduced physical function, physical activity and gait speed. We recently developed a valid and reliable RFD testing protocol using a hand-held dynamometer (HHD) and freely-available software [1]. However, the clinical relevance of this protocol is yet to be assessed in people following TKR.

Hypothesis: Greater quadriceps strength/RFD would be associated with better knee function, higher physical activity levels and greater gait speed.

Methods: Fifty-five people (26 women, mean age 69±8, mean 4±1 months post TKR) volunteered to participate. Quadriceps peak torque and RFD were assessed in 90 degrees knee flexion using a Lafayette HHD. RFD was calculated using custom software. Knee pain (VAS), knee function (Oxford scale), physical activity (International Physical Activity Questionnaire) and gait speed (6-metre walk test) were assessed concurrently. Pearson r values were used to determine associations between variables.

Results: The operated limb had significantly lower body-weight-normalized quadriceps strength (p<0.001, 31% difference) and RFD (p<0.001, 32% difference) than the contralateral side. There were no significant associations between quadriceps strength/RFD and knee pain, knee function or physical activity. There were significant moderate correlations between gait speed and quadriceps RFD on the operated (r=0.45) and contralateral side (r=0.57) and quadriceps strength on the contralateral side (r=0.46).

Conclusion: Quadriceps RFD on either limb may be an important determinant of gait speed following TKR.

Mentiplay BF, Perraton LG, Bower KJ, Adair B, Pua Y-H, Williams GP, et al. (2015) Assessment of lower limb muscle strength and power using hand-held and fixed dynamometry: a reliability and validity study. PloS one 10:e0140822