Hamstring muscle tear with recurrent complaints: An isokinetic profile

Article type: Research Article

Authors: Croisier, Jean-Louis^a | Crielaard, Jean-Michel^a

Affiliations: [a] Department of Physical Medicine and Rehabilitation, CHU Sart Tilman, B.35, 4000 Li\`ege, Belgium

Note: [] ISEPK, B21, Allée des Sports 4, B-4000 Li\`ege, Belgium. Tel.: +32 4 366 38 91; Fax: +32 4 366 72 30; E-mail: jlcroisier@ulg.ac.be

Abstract: The purpose of this study was to determine the isokinetic profile of specialized athletes with previous hamstring tears and recurrent complaints upon return to sports activities, using a Kintrex 500 dynamometer. Twenty-three subjects were examined through a concentric protocol and fifteen of them benefited from a complementary eccentric assessment. Despite the fact that some cases presented normal isokinetic results, the statistical analysis has demonstrated particular features. In reference to the non-involved side performances, the average reduction of peak torque (PT) of the injured muscles surpassed 20% relationship between bodyweight normalized PT and angular velocity demonstrated significant differences in comparison with those of selected non-injured sprinters, most notably in the eccentric sector. A mixed ratio (Flexors_{\rm eccentric}/Quadriceps_{\rm concentric}) appeared significantly reduced (0.75 \pm 0.23) for the injured leg, in comparison with the contralateral non-injured limb (0.90 \pm 0.16) and with a control population (0.98 \pm 0.14). For the eccentric mode, the angle of peak torque (APT) of the strained muscle occurred in an abnormal articular sector corresponding to a weaker hamstring muscle lengthening than normal. These observations strongly suggest that, among the causative factors, the persistence of muscle strength abnormalities gives rise to recurring hamstring injuries.

DOI: 10.3233/IES-2000-0048

Journal: Isokinetics and Exercise Science, vol. 8, no. 3, pp. 175-180, 2000