Int J Sports Med
DOI: 10.1055/a-1398-5501
Clinical Sciences

Immediate Effects of two Isometric Calf Muscle Exercises on Mid-portion Achilles Tendon Pain

Ben Bradford
1  Faculty of Medicine and Health Sciences, University of East Anglia, Norwich, United Kingdom of Great Britain and Northern Ireland
,
Ebonie Rio
2  LASEM Research Centre, La Trobe University - Bundoora Campus, Melbourne, Australia
,
Myles Murphy
3  School of Physiotherapy, The University of Notre Dame Australia, Fremantle, Australia
,
Jacob Wells
1  Faculty of Medicine and Health Sciences, University of East Anglia, Norwich, United Kingdom of Great Britain and Northern Ireland
,
Mizanur Khondoker
4  Norwich Medical School, University of East Anglia, Norwich, United Kingdom of Great Britain and Northern Ireland
,
Celia Clarke
1  Faculty of Medicine and Health Sciences, University of East Anglia, Norwich, United Kingdom of Great Britain and Northern Ireland
,
York Chan
5  Physiotherapy Department, Ipswich Hospital NHS Trust, Colchester, United Kingdom of Great Britain and Northern Ireland
,
Rachel Chester
1  Faculty of Medicine and Health Sciences, University of East Anglia, Norwich, United Kingdom of Great Britain and Northern Ireland
› Author Affiliations
Funding Ben Bradford is funded by a National Institute for Health Research (NIHR) pre-doctoral Clinical Academic Fellowship for this research project. Dr Ebonie Rio is a National Health and Medical Research Council funded post-doctoral fellow. This publication presents independent research funded by the National Institute for Health Research (NIHR).

Abstract

The objectives of this randomized, cross-over pilot study were to determine whether isometric plantarflexion exercises resulted in an immediate change in Achilles tendon pain during a loading task, and whether this differed in knee extension or flexion. Eleven participants with mid-portion Achilles tendinopathy were recruited from NHS community physiotherapy services and local running clubs. Participants were then randomized to complete an isometric calf muscle exercise with the knee fully extended or flexed to 80°. Participants switched to the alternate exercise after a minimum seven-day period. Achilles tendon pain during a specific, functional load test was measured on a 11-point numeric pain rating scale (NPRS) pre- and post-intervention. There was a small, immediate, mean reduction in pain following isometric plantar flexion performed in both knee extension (1.6, 95%CI 0.83 to 2.45, p=0.001) and knee flexion (1.3, 95%CI 0.31 to 2.19, p=0.015). There were no significant differences between the two positions. A non-significant, potentially clinically relevant finding was a 20% larger reduction in symptoms in knee extension versus flexion (p=0.110). In conclusion, isometric plantarflexion holds gave an approximately 50% immediate reduction in Achilles tendon pain with a functional load test. There were no significant differences between the two positions and both were well tolerated.

Supplementary Material



Publication History

Received: 03 August 2020

Accepted: 01 February 2021

Publication Date:
29 March 2021 (online)

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