Squat : Effect of exercise to reduce Knee Valgus

Original Citation:

Bell, D. R., Oates, D. C., Clark, M. A., & Padua, D. A. (2013). Two-and 3-dimensional knee valgus are reduced after an exercise intervention in young adults with demonstrable valgus during squatting. Journal of athletic training,48(4), 442-449. ABSTRACT 


Review:(Level 2b)

The methodology of this study was quite strong. The researchers took care to standardize the performance of the DLS task with a tripod to mark a depth of 90 degrees of knee flexion, in addition to using markers for foot position to ensure that there were no changes with multiple repetitions. The selection of subjects was highly specific, and focused on those with MKD related to ankle dysfunction.

Subjects participated in (10) 30-minute sessions over a 3- week period. The Exercise Progression was achieved by increasing resistance, sets & reps. The researcher who performed strength & ROM measurements. It was not blinded to the subject’s group assignment. There was no long-term follow-up with the subjects to determine if they retained a reduction in knee valgus over time. We think that if the authors included a more detailed description of the exercises in the intervention programme.

Moreover, it would have been interesting that to include strength tests of ankle as well as hip musculature & range of motion measurements. This helps in pre-post test measures to see how these parameters changes as DLS performance improved. Knee valgus was not significantly different between groups.

Additionally, the authors explain in detail about previous research. They noted that analysis of 3D & 2D data relating to knee valgus do not necessarily correlate. This is an interesting observation.

The authors states that they did not see significant increases in hip strength at post-test. It may be due to specificity of subject selection. It is to focus on ankle dysfunction, therefore hip weakness was not present. The gluteus maximus and gluteus medius were not included as part of the intervention programme. They involved in the integrated balance exercises. Other Authors have not found consistent results with respect to the role of hip strength in knee valgus.

How does it affect practice?

This study provides information on a specific intervention for a specific group of individuals. We can use this programme with patients who have same characteristic of the subject in this study.