The aim of this study was to develop an isokinetic quadriceps muscle strength curve profile for ACL-injured subjects in general, and also after classification of the subjects as potential copers (with adequate ability to compensate for their injury) and non-copers (with poor ability to compensate for their injury).


Based on angle-specific mean relative strength torque values throughout a knee extension range of motion from 80° to 15° knee flexion, detailed quadriceps muscle strength curve profiles were developed both for the overall group and for potential

copers and non-copers.


The main finding revealed that quadriceps muscle strength deficits were most prominent at knee flexion angles less than 40° knee flexion. This characteristic curve profile was more pronounced for individuals classified as non-copers.


These findings suggest that the established use of peak torque as main outcome for isokinetic strength may conceal important quadriceps muscle strength deficits after ACL injury. Consequently, quadriceps muscle strength should also be evaluated in knee joint angles close to full extension.


PhD student Ingrid Eitzen from the Norwegian Research Center of Active Rehabilitation was the main investigator of this study (link til studien).


To more studies were publised by NAR in january in American Journal of Sports Medicine and in Journal of Bone and Joint Surgery:


(1) Holm I, Øiestad BE, Risberg MA, Aune AK. No Difference in Knee Function or Prevalence of Osteoarthritis After Reconstruction of the Anterior Cruciate Ligament With 4-Strand Hamstring Autograft Versus Patellar Tendon–Bone Autograft. A Randomized Study With 10-Year Follow-up


This study aimed to compare the long term knee function and prevalence of knee osteoarthritis (OA) for two randomized groups treated with either patellar tendon bone reconstruction or hamstrings tendon reconstruction after anterior cruciate ligament (ACL) rupture. 


The study was a randomized study with 10 years follow-up. Fifty-seven subjects (29 with hamstrings graft and 28 with patellar tendon graft) were evaluated 10 years after the reconstruction. No significant differences were found between the two graft choices with respect to knee function, or development of radiographic knee OA (link til studien).


(2) LaPrade RF, Johansen S, Agel J, Riseberg MA, Moksnes H, Engebretsen L. Outcomes of an Anatomic Posterolateral Knee Reconstruction (link til studien).