Loughborough University
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Bilateral impairments of quadriceps neuromuscular function occur early after anterior cruciate ligament injury

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posted on 2022-05-26, 08:32 authored by Jihong Qiu, Tianzhi Jiang, Michael Tim-Yun Ong, Xin He, Chi-Yin Choi, Sai-Chuen Fu, Daniel FongDaniel Fong, Patrick Shu-Hang Yung

The study aimed to investigate the impairments in quadriceps neuromuscular function, including strength, rate of torque development (RTD) and activation failure (QAF) early after an ACL injury. A cross-sectional study was conducted. Thirty physically active patients with a primary ACL injury within three months, aged 18 to 40 years old, and who were scheduled for ACL reconstruction were included. Thirty matched healthy controls were also recruited. All the outcomes were measured on an isokinetic dynamometer with knee flexion at 45°. Quadriceps strength was measured by maximal voluntary isometric contractions (MVIC). Early (RTD0-50) and late (RTD100-200) phases of RTD were retrieved from the MVIC test from 0 to 50 ms and 100–200 ms, respectively. QAF was quantified by the central activation ratio (CAR) measured by superimposed burst technique. The results of Mann–Whitney U test showed that compared with the healthy limbs, the injured limbs of the ACL group showed lower quadriceps strength (P < 0.001), RTD0-50 (P < 0.001) and RTD100-200 (P < 0.001); the uninjured limbs showed lower quadriceps strength (P = 0.009), RTD0-50 (P = 0.006) as well as greater QAF (P = 0.010). To conclude, bilateral quadriceps suffered from neuromuscular impairments early after an ACL injury.



  • Sport, Exercise and Health Sciences

Published in

Research in Sports Medicine


Taylor & Francis


  • AM (Accepted Manuscript)

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© Taylor & Francis

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This is an Accepted Manuscript of an article published by Taylor & Francis in Research in Sports Medicine on 29 May 2022, available at: http://www.tandfonline.com/10.1080/15438627.2022.2079986.

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Dr Daniel Fong. Deposit date: 25 May 2022

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