Erratum to "Design of patient-specific gait modifications for knee osteoarthritis rehabilitation"

Abstract

Abstract-Gait modification is a nonsurgical approach for reducing the external knee adduction torque in patients with knee osteoarthritis (OA). The magnitude of the first adduction torque peak in particular is strongly associated with knee OA progression. While toeing out has been shown to reduce the second peak, no clinically realistic gait modifications have been identified that effectively reduce both peaks simultaneously. This study predicts novel patient-specific gait modifications that achieve this goal without changing the foot path. The modified gait motion was designed for a single patient with knee OA using dynamic optimization of a patient-specific, full-body gait model. The cost function minimized the knee adduction torque subject to constraints limiting how much the new gait motion could deviate from the patient's normal gait motion. The optimizations predicted a "medial-thrust" gait pattern that reduced the first adduction torque peak between 32% and 54% and the second peak between 34% and 56%. The new motion involved three synergistic kinematic changes: slightly decreased pelvis obliquity, slightly increased leg flexion, and slightly increased pelvis axial rotation. After gait retraining, the patient achieved adduction torque reductions of 39% to 50% in the first peak and 37% to 55% in the second one. These reductions are comparable to those reported after high tibial osteotomy surgery. The associated kinematic changes were consistent with the predictions except for pelvis obliquity, which showed little change. This study demonstrates that it is feasible to design novel patient-specific gait modifications with potential clinical benefit using dynamic optimization of patient-specific, full-body gait models. Further investigation is needed to assess the extent to which similar gait modifications may be effective for other patients with knee OA.

A Biomechanical Perspective on Physical Therapy Management of Knee Osteoarthritis

“…In a single-subject study, modeling simulations of the medial-thrust gait pattern in a patient with knee OA predicted reductions of as high as 50% for the first peak and 55% for the second peak in KAM (TABLE 5). 67 A recent study of systematic training of medial-thrust gait pattern using real-time knee alignment feedback also reported a 19% decrease in KAM after only 8 training sessions in 8 asymptomatic but varus-aligned individuals.…”

“…87,202 Theoretically, interventions aimed at decreasing lower-limb varus malalignment, such as valgus bracing 45,46,104,149 or a medial thrust gait pattern, 11,66,165 can bring the knee center of rotation closer to the line of action of the GRF and thus decrease KAM by reducing its frontal plane lever arm. Similarly, moving the GRF vector closer to the knee center of rotation by moving the center of pressure laterally through a lateral trunk lean 89,137 or a toe-out gait pattern 67,100,124 could also be effective in reducing KAM by shortening its frontal plane lever arm.…”

“…11 As a medial-thrust gait has been associated with a tendency for an undesired increase in the peak knee flexion moment, 67,201 efforts to train patients with medial knee OA to perform a medial-thrust gait pattern (if indicated) should emphasize a minimal increase in knee flexion angle during gait. 201 Further modification of daily activities or occupational factors by teaching new methods of performing daily tasks or by changing requirements of the desired activities should also be considered as a long-term treatment option.…”

The Effects of Yoga and Medial Thrust Gait Training and Conventional Physiotherapy on Gait Biomechanics, Pain, and Function in Individuals with Knee Osteoarthritis: A Randomized Clinical Trial Protocol

“…More recent studies showed that voluntary changes in gait pattern, including toe-out gait (22,23), relatively slow walking (24), increasing mediolateral trunk sway (22,25) and medial thrust (MT) gait (26)(27)(28) may decrease the KAM in knee OA. MT gait, walking with knee internal rotation, is preferable to other gait modifications because it resembles the normal gait, and causes a higher reduction of the first and second peaks of KAM when compared with other gait modification techniques in vitro study (28).…”

The impact of hip implant alignment on muscle and joint loading during dynamic activities

“…Musculoskeletal simulation offers valuable data to clinicians and researchers assessing pathological conditions and understanding human movement. Simulation of human movement has significantly impacted approaches to clinical treatment of osteoarthritis (Fregly et al, 2007) and total joint replacement (Gaffney et al, 2015; Navacchia et al, 2016), as well as basic science related to the understanding of movement progression and control during dynamic tasks (Anderson et al, 2004; Neptune et al, 2009; Zajac et al, 2002). There have been a number of impactful innovations in simulation methods from sophisticated subject-specific models with highly accurate anatomic detail (Arnold et al, 2010), to creation of efficient forward dynamics simulations using computed muscle control (Thelen and Anderson, 2006) that make it possible to address variation in component positioning across multiple patients.…”