Exercise Affects Cortical Inhibition & Reduces Pain In Patellar Tendinopathy: Randomised Cross Over Trial

Ebonie K. Rio, Jill Cook, Dawson Kidgell

Research output: Contribution to journalMeeting AbstractOtherpeer-review

Abstract

INTRODUCTION: Patellar tendinopathy (PT) affects the ability to jump and land due to pain and associated corticospinal changes to motor patterning. There is a need for interventions that reduce pain immediately, enabling participation in sport yet do not negatively impact on muscle fatigue.The purpose of this study was to compare a bout of either isometric or isotonic muscle contractions on tendon pain and function and quad strength. METHODS: This was a cross over design with baseline testing and two intervention arms. Baseline testing consisted of single leg decline squat score/ten & measures to assess corticospinal excitation and inhibition.Six male volleyball athletes with PT completed all sessions one week apart with the order of intervention randomized. The isometric muscle contraction protocol consisted of 5 x 45 seconds at 70% of their maximal voluntary isometric contraction. The isotonic protocol consisted of 4 x 8 repetitions (3 sec concentric phase and 4 sec eccentric phase) at 100% of their 8 repetition maximum. The protocols were matched for time under load and rest between sets. RESULTS: All participants at baseline demonstrated high levels of inhibition ratio (24.3% ± 12) compared with normal data for the quadriceps (reported 50-70%). At baseline single leg decline squat pain was mean 6.75/10. Isometric muscle contractions significantly reduced patellar tendon pain immediately regardless of the order of intervention (mean 0.16/10 range 0- 1, p<0.001). Isometric muscle contractions resulted in sustained pain relief for up to 45 minutes post intervention, whereas the isotonic intervention demonstrated only immediate and non-significant pain reduction. Cortical inhibition ratio was reduced following isometric contractions to 50% (near normal values) regardless of the order of intervention. DISCUSSION: Isometric contractions reduce tendon pain immediately & for at least 45 min post intervention and do not cause a reduction is strength. The clinical implications are that isometric muscle contractions may be used to reduce pain prior to sport without resulting in muscle fatigue that may impact on performance. Whilst isotonic has been shown to be effective for tendon rehabilitation, this may not be appropriate immediately prior to activity due to the effects on muscle fatigue.
Original languageEnglish
Pages (from-to)209-210
Number of pages2
JournalMedicine and Science in Sports and Exercise
Volume46
Issue number1 5S
Publication statusPublished - May 2014
EventAmerican College of Sports Medicine Annual Meeting 2014 - Orlando, United States of America
Duration: 27 May 201431 May 2014
Conference number: 61st

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