Knee alignment with and without implements in leg press and squat exercises: a systematic review

Resistance training has been commonly used as a method of intervention in the rehabilitation of musculoskeletal injuries affecting the knee. Thus, the objective of this systematic review was to identify the methods employed with and without implements in leg press and squat exercises for the maintenance of knee alignment. The literature search was performed in the databases: PubMed, SciELO, and Lilacs. We used the descriptors "muscle strength" and "exercise" and their synonyms, available in the Health Sciences Descriptors (DeCS) and the Medical Subject Headings (MeSH), with the terms "valgus knee" and "varus knee". From the 1,117 articles found, eight studies were considered for the review. The included studies had samples composed of young men and women with advanced levels of training. Despite verifying conditions of valgus or varus knee, the studies presented different protocols and assessment methods. The implements comprised physioball, elastic resistance, and wedge. Electromyography and kinematics were used to assess muscle activity and movement patterns. These results reinforced the possibility of using implements to induce muscle and joint actions to reduce varus and valgus conditions. We suggest more studies to define the best strategies to reduce the excessive deviation of the patella in people who have valgus or varus knee.