Valgus knee braces reduce the net knee adduction moment during walking in healthy young adults and in patients with medial knee arthritis. Considering, therefore, that valgus knee bracing predominantly affects the net knee adduction moment, studies indicating that the external knee adduction moment decreases with bracing suggest that this approach has additional benefits for unloading the medial compartment of the knee.

The decrease in the external knee adduction moment observed in individuals wearing a valgus knee brace could be related to a medial shift in the knee joint center leading to a reduction in the knee adduction moment arm.

Knee braces can be adjusted to increase the extent of valgus alignment, which also increases the valgus moment applied at the knee joint.

The peak net knee adduction moment progressively decreased with increasing valgus alignment of the knee brace.

A neutrally aligned knee brace reduced the peak net knee adduction moment by 6% compared with the unbraced situation, whereas valgus brace alignments of 4° and 8° yielded reductions of 13% and 19%, respectively.

These reductions in net knee adduction moment were estimated to give rise to decreases of between 8% and 17% in medial knee compartment loading during walking. Estimations derived from a musculoskeletal model suggest that for every 1 Nm increase in the valgus brace moment, the net knee adduction moment decreases by 3% and the medial compartment load decreases by 1%.

These estimates are in agreement with fluoroscopic imaging data from a study of patients with medial knee arthritis. 80% of these patients experienced a 2 mm increase in medial tibiofemoral joint separation while walking with a valgus knee brace compared with the unbraced control situation. However, the 20% of patients who were obese did not derive any benefit from valgus knee bracing.

Although obese patients experience high joint loads that could partially explain their impaired response to bracing, the researchers ascribed this observation to problems with adequate fixation of the knee brace. Excessive amounts of soft tissue seem likely to reduce the effective transmission of forces from the knee brace to the femur and tibia.

Pain is a cardinal symptom of knee joint arthritis, and a valgus knee brace substantially reduced arthritis pain for these patients immediately upon use, and after continuous wear for durations ranging between 2 weeks and 12 months.

Improvements in function have also been reported in patients with OA following valgus knee bracing for durations of between 6 months and 12 months.

Although valgus bracing achieves effective unloading of the medial compartment of the knee and offers potential for improving the clinical outcome in patients with knee arthritis pain, the success of this intervention relies upon the patient being prepared to wear the knee brace continually.

Valgus knee braces are bulky, potentially uncomfortable and might not be a practical daily solution for many patients.