Effect of variable‐stiffness walking shoes on knee adduction moment, pain, and function in subjects with medial compartment knee osteoarthritis after 1 year

Abstract

This study investigated the load-modifying and clinical efficacy of variable-stiffness shoes after 12 months in subjects with medial compartment knee osteoarthritis. Subjects who completed a prior 6-month study were asked to wear their assigned constantstiffness control or variable-stiffness intervention shoes during the remainder of the study. Changes in peak knee adduction moment, total Western Ontario and McMaster Universities (WOMAC), and WOMAC pain scores were assessed. Seventy-nine subjects were enrolled, and 55 completed the trial. Using an intention-to-treat analysis, the variable-stiffness shoes reduced the within-day peak knee adduction moment (À5.5%, p < 0.001) in the intervention subjects, while the constant-stiffness shoes increased the peak knee adduction moment in the control subjects (þ3.1%, p ¼ 0.015) at the 12-month visit. WOMAC pain and total scores for the intervention group were significantly reduced from baseline to 12 months (À32%, p ¼ 0.002 and À35%, p ¼ 0.007, respectively). The control group had a reduction of 27% in WOMAC pain score (p ¼ 0.04) and no significant reduction in total WOMAC score. Reductions in WOMAC pain and total scores were similar between groups (p ¼ 0.8 and p ¼ 0.47, respectively). In the intervention group, reductions in adduction moment were related to improvements in pain and function (R 2 ¼ 0.11, p ¼ 0.04). Analysis by disease severity revealed greater efficacy in adduction moment reduction in the less severe intervention group. While the long-term effects of the intervention shoes on pain and function did not differ from control, the data suggest wearing the intervention shoe reduces the within-day adduction moment after long-term wear, and thus should reduce loading on the affected medial compartment of the knee. ß

The relationship between patellofemoral and tibiofemoral morphology and gait biomechanics following arthroscopic partial medial meniscectomy

“…However, alignment is one factor that influences 22 the magnitude of the knee adduction moment, with poor alignment causing large 23 frontal plane lever arm lengths and thus implicitly produces large knee adduction 24 moment measures. 25 The results from this study suggest that interventions targeting gait biomechanics 1 following APMM may result in improved patient outcomes. Interventions such 2 as gait retraining [18,31], valgus thrust braces [19,29], modified footwear [14] 3 and lateral wedge insoles [15,16] have been shown to reduce knee adduction 4 moments.…”

“…MRI of the participants' operated knee was performed on 1.5-T whole body magnetic resonance units (City 1: Magnetom Symphony, Siemens, Erlangen, Germany; City 2: Phillips, Philips Medical Systems, Eindhoven, the Netherlands), using the sequence and parameters as previously described [25]. Body mass and height were measured in light clothing with no footwear, and body mass index (BMI) calculated.…”

“…It has previously been demonstrated that decreases in cartilage volume and increases in subchondral bone area [8,20] precede semi-quantitative measures of joint space narrowing measured from x-rays. Other changes that can be identified earlier using MRI include cartilage defects and changes in cartilage volume [9,25].…”

A Biomechanical Perspective on Physical Therapy Management of Knee Osteoarthritis

“…Variable-stiffness shoes have been shown to significantly reduce the first peak in KAM by as much as 13% compared to constant-stiffness control shoes (TABLE 3). [41][42][43][44]99 Given that the magnitude of the GRF remains relatively unchanged when wearing variable-stiffness shoes, it has been suggested that reductions in KAM are related to a lateral shift in the center of pressure at the foot, which reduces the external KAM lever arm. 99 An instrumented knee replacement prosthesis that directly measured knee loading in a single patient found reductions of 13% in the first peak in KAM, 22% in the second peak in KAM, and 12% in the medial compartment joint contact force when walking with variable-stiffness shoes compared to personal shoes.…”

“…41 Clinical evidence also supports the effectiveness of variable-stiffness shoes in reducing knee pain and improving function after 6 and 12 months of continuous use. 42,44 Therefore, the use of variable-stiffness shoes seems to be an effective treatment strategy for reducing symptoms and medial compartment loading for patients with knee OA during gait.…”