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Hamstring antagonist torque generated in vivo following ACL rupture and ACL reconstruction

Journal Article


Abstract


  • Hamstring motor behaviour and resultant antagonist torque during knee extension has been quantified in

    uninjured individuals however, the effect of ACL rupture and ACL reconstruction (ACLR) on the morphology of hamstring antagonist torque generated in vivo is unknown. The purpose of this cross-sectional study was to quantify the hamstring antagonist torque generated in vivo during isokinetic knee extension in ACLD and ACLR patients relative to uninjured control subjects. Ten male ACL deficient (ACLD) subjects (18–35 years), 14 matched males who had undergone ACLR using the bone–patellar tendon–bone graft and 22 matched male control subjects participated. We used a mathematical model to estimate the opposing torque generated by the hamstrings during isokinetic knee extension in 10° intervals from 80° to 10° knee flexion. Control group hamstring antagonist torque was significantly lower at 80–70° knee flexion compared with that of the ACLD (% Diff=40.2; p=0.019) and ACLR (% Diff=34.8; p=0.036) groups. For all subject groups, hamstring antagonist torque demonstrated a descending–ascending curve; decreasing significantly from 80– 70° to 50–40° knee flexion (% Diff=40.8 to 63.3; p=b0.001 to 0.009) but then increasing significantly from 50–40° to 20–10° knee flexion (% Diff=37.6 to 59.0; p=b0.001 to 0.012). ACL status and therefore, the ACLhamstring reflex has little effect on the magnitude of hamstring antagonist torque generated during quadriceps-induced knee joint loading. Capsular afferents are thought to dictate the hamstring torque profile which decreased then increased during knee extension to maintain dynamic joint stability.

Authors


  •   Bryant, Adam (external author)
  •   Creaby, Mark (external author)
  •   Newton, Robert U. (external author)
  •   Steele, Julie R.

Publication Date


  • 2010

Published In


Citation


  • Bryant, A., Creaby, M., Newton, R. & Steele, J. R. (2010). Hamstring antagonist torque generated in vivo following ACL rupture and ACL reconstruction. Knee, 17 (4), 287-290.

Scopus Eid


  • 2-s2.0-77953712357

Ro Metadata Url


  • http://ro.uow.edu.au/hbspapers/3423

Number Of Pages


  • 3

Start Page


  • 287

End Page


  • 290

Volume


  • 17

Issue


  • 4

Place Of Publication


  • http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6TCJ-4YK88YG-1-3&_cdi=5172&_user=202616&_pii=S0968016010000384&_orig=browse&_coverDate=08%2F31%2F2010&_sk=999829995&view=c&wchp=dGLbVzb-zSkzk&md5=82728d3da42c6a0cc859285c93d4cded&ie=/sdarticle.pdf

Abstract


  • Hamstring motor behaviour and resultant antagonist torque during knee extension has been quantified in

    uninjured individuals however, the effect of ACL rupture and ACL reconstruction (ACLR) on the morphology of hamstring antagonist torque generated in vivo is unknown. The purpose of this cross-sectional study was to quantify the hamstring antagonist torque generated in vivo during isokinetic knee extension in ACLD and ACLR patients relative to uninjured control subjects. Ten male ACL deficient (ACLD) subjects (18–35 years), 14 matched males who had undergone ACLR using the bone–patellar tendon–bone graft and 22 matched male control subjects participated. We used a mathematical model to estimate the opposing torque generated by the hamstrings during isokinetic knee extension in 10° intervals from 80° to 10° knee flexion. Control group hamstring antagonist torque was significantly lower at 80–70° knee flexion compared with that of the ACLD (% Diff=40.2; p=0.019) and ACLR (% Diff=34.8; p=0.036) groups. For all subject groups, hamstring antagonist torque demonstrated a descending–ascending curve; decreasing significantly from 80– 70° to 50–40° knee flexion (% Diff=40.8 to 63.3; p=b0.001 to 0.009) but then increasing significantly from 50–40° to 20–10° knee flexion (% Diff=37.6 to 59.0; p=b0.001 to 0.012). ACL status and therefore, the ACLhamstring reflex has little effect on the magnitude of hamstring antagonist torque generated during quadriceps-induced knee joint loading. Capsular afferents are thought to dictate the hamstring torque profile which decreased then increased during knee extension to maintain dynamic joint stability.

Authors


  •   Bryant, Adam (external author)
  •   Creaby, Mark (external author)
  •   Newton, Robert U. (external author)
  •   Steele, Julie R.

Publication Date


  • 2010

Published In


Citation


  • Bryant, A., Creaby, M., Newton, R. & Steele, J. R. (2010). Hamstring antagonist torque generated in vivo following ACL rupture and ACL reconstruction. Knee, 17 (4), 287-290.

Scopus Eid


  • 2-s2.0-77953712357

Ro Metadata Url


  • http://ro.uow.edu.au/hbspapers/3423

Number Of Pages


  • 3

Start Page


  • 287

End Page


  • 290

Volume


  • 17

Issue


  • 4

Place Of Publication


  • http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6TCJ-4YK88YG-1-3&_cdi=5172&_user=202616&_pii=S0968016010000384&_orig=browse&_coverDate=08%2F31%2F2010&_sk=999829995&view=c&wchp=dGLbVzb-zSkzk&md5=82728d3da42c6a0cc859285c93d4cded&ie=/sdarticle.pdf