Quadriceps torque curve pattern in patients with anterior cruciate ligament injury

Abstract

We measured torque curve pattern and quadriceps muscle strength with the knee slightly flexed in 48 patients with an anterior cruciate ligament injury, and analyzed the factors associated with reduced quadriceps strength. Strength was measured under isokinetic contraction, and concentric and eccentric contractions were studied. Strength was significantly lower in the injured knee, which also showed abnormal patterns of torque curve. In addition to the rapid downward slope pattern usually associated with concentric contraction, there was a concave pattern during eccentric contraction.Résumé Nous avons mesuré le moment de rotation et la force du quadriceps à la flexion légère du genou chez 48 malades ayant une lésion du ligament croisé antérieur (ACL), et a analysé les facteurs associé s à l'affaiblissement de la force quadricipitale. La force des quadriceps a été mesurée sous contraction isocinétique, et les contractions concentriques et excentriques ont été étudiées. La force des quadriceps était considérablement inférieure sur le genou blessé comparé au genou opposé, indemne. Le genou blessé a aussi montré des modèles de moment de rotation distinct des modèles normaux. En plus de la rapide décroissance habituellement rapportée pendant la contraction concentrique, un modèle concave a été observé pendant la contraction excentrique.

Frequency content asymmetry of the isokinetic curve between ACL deficient and healthy knee

“…Solomonow et al (1987) attributed the irregular pattern of the isokinetic curve in ACL deficient patients to the temporary subluxating tibia. This observation has been confirmed by others as well, although not in a numerical manner (Dvir et al, 1991;Ikeda, 2002;Ayalon et al, 2002). Apart from the aforementioned mechanical disturbance, there seems to be a direct link between ACL and muscles around the knee (Dyhre-Poulsen and Krogsgaard, 2000).…”

“…Anterior cruciate ligament (ACL) injury has various negative implications for thigh muscle function, including reduction of muscle strength (Lorentzon et al, 1989;Wojtys and Huston, 2000a, b) and instability of torque generation (Dvir, 1995;Ikeda, 2002). Extension and flexion strength after ACL rupture is assessed by isokinetic dynamometry, which involves measurements mainly of the classical parameters such as peak torque, total work and average power (Benjuya et al, 2000;St.…”

Neuromuscular adaptations and correlates of knee functionality following ACL reconstruction

“…Westing et al 14 demonstrated that the method error and standard deviation for this measure is approximately 8% and 13 NÁm, respectively. With 80% power and an alpha level error of 5%, at least 10 subjects were needed to detect greater than the clinically significant difference in knee extensor strength (approximately 11%; Kannus et al 15 ; McNair 16 ; Keays et al 17 ; Ikeda et al 18 ) between test limbs. This study was approved by the Human Ethics Research Review Panel, Central Queensland University, Rockhampton, Australia.…”

Neuromuscular Control of the Knee during a Resisted Single-Limb Squat Exercise

“…Recovery after knee joint injury is complicated by persistent quadriceps weakness, decreased joint stability, and deficits in proprioception, all of these factors resulting in decreased neuromuscular control. 11,13,14 During the past decade, knee rehabilitation after ACL reconstruction has undergone a tremendous evolution, from a conservative approach of immobilization for 6 to 8 weeks followed by crutch training for 8 to 12 weeks, to functional rehabilitation that emphasizes immediate motion and weightbearing. 26 Proprioceptive training is also gaining recognition as an integral component of rehabilitation.…”