Objectives To review the literature regarding gait retraining to reduce knee adduction moments and their effects on hip and ankle biomechanics. Data Sources Twelve academic databases were searched from inception to January 2019. Key words “walk*” OR “gait,” “knee” OR “adduction moment,” “osteoarthriti*” OR “arthriti*” OR “osteo arthriti*” OR “OA,” and “hip” OR “ankle” were combined with conjunction “and” in all fields. Study Selection Abstracts and full-text articles were assessed by 2 individuals against a predefined criterion. Data Synthesis Of the 11 studies, sample sizes varied from 8-40 participants. Eight different gait retraining styles were evaluated: hip internal rotation, lateral trunk lean, toe-in, toe-out, increased step width, medial thrust, contralateral pelvic drop, and medial foot weight transfer. Using the Black and Downs tool, the methodological quality of the included studies was fair to moderate ranging between 12 of 25 to 18 of 28. Trunk lean and medial thrust produced the biggest reductions in first peak knee adduction moment. Studies lacked collective sagittal and frontal plane hip and ankle joint biomechanics. Generally, studies had a low sample size of healthy participants with no osteoarthritis and assessed gait retraining during 1 laboratory visit while not documenting the difficulty of the gait retraining style. Conclusions Gait retraining techniques may reduce knee joint loading; however, the biomechanical effects to the pelvis, hip, and ankle is unknown, and there is a lack of understanding for the ease of application of the gait retraining styles.

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Objective With an increasingly ageing population and osteoarthritis prevalence, the quantification of nociceptive signals responsible for painful movements and individual responses could lead to better treatment and monitoring solutions. Changes in electrodermal activity (EDA) can be detected via changes in skin conductance (SC) and measured using finger electrodes on a wearable sensor, providing objective information for increased physiological stress response. Results To provide EDA response preliminary data, this was recorded with healthy volunteers on an array of activities while receiving a noxious stimulus. This provides a defined scenario that can be utilised as protocol feasibility testing. Raw signal extraction, processing and statistical analysis was performed using mean SC values on all participant data. Extra exploratory analysis on a case study was incorporated using various decomposition tools. The application of the stimuli resulted in a 35% average increase in mean SC with considerable gender differences in SC and self-reported pain scores. Though EDA parameters are a promising tool for nociceptive response indicators, limitations including motion artifact sensitivities and lack of previous movement-based EDA published data result in restricted analysis understanding. Refined processing pipelines with signal decomposition tools will be necessary to incorporate into a protocol that quantifies nociceptive response clinically meaningfully.

Tibial articular surface deforms by the bone defects and articular wear with progression of medial knee osteoarthritis (knee OA). It will affect the kinematics of knee joint and lower extremity under various loading conditions, however the detail of this mechanism has not been clarified enough. The purpose of this study was to investigate the effect of tibial articular surface deformity on the kinematics of lower extremity during level in some severities of medial knee OA. Methods: Subjects were 57 knees in 50 adults (18 males and 32 females, age: 56.6±19.2y.o.). Medial knee OA severity was graded by the Kellgren and Lowrence classification (grade-0: 8 knees,-I: 8 knees,-II: 15 knees,-III: 18 knees and-IV: 8 knees). The deformity of tibial articular surface was analyzed by their computed tomography-based three-dimensional (3D) bone model, and the tilt of articular surface was evaluated as the angle of articular surface relative to the long axis of tibia on the frontal plane. Level walking of the subject was measured by a motion capture system at a sampling rate of 250Hz (VICON, Vicon Motion Systems, Ltd, UK), and then the kinematics of femur and tibia relative to the ground during level walking was estimated by combining the motion capture data and the femorotibial bone models. Knee-joint kinematics was evaluated as tibial motion relative to femur. Additionally, stride length and walking velocity were assessed as walking performance. The differences in the parameter among knee OA severities were analyzed statistically by the Kruskal-Wallis test (alpha ¼ 5%). Results: Following several tendencies indicated with progression of knee OA: (1) The tibial articular surface tilted medially relative to the long axis of tibia (p<0.05); (2) The stride length and walking velocity decreased significantly (p<0.01); (3) The peak of knee flexion angle decreased (p<0.01), and the peak of knee varus angle increased (p<0.01); (4) The tibial and femoral long axes during stance phase tilted to the lateral and medial sides relative to the vertical axis of the ground, respectively (p<0.01); (5) The tilt of tibial articular surface relative to the ground demonstrated no significant difference among knee OA severities. Conclusions: The knee-joint line during the stance phase kept the constant tilt relative to ground with progression of knee OA. The deformity of tibial articular surface affected to the kinematics of tibia relative to the ground during the stance phase. The results of this study indicated that the femoral motion relative to tibia during the stance phase was mainly regulated by the deformity of tibial articular surface. Consequently, there was the possibility that the deformity of tibial articular surface became stronger than healthy condition by the imbalance of contact force and the increased shear force on the tibial articular surface under the loading condition. These findings may be helpful to improve the implant placement of total knee arthroplasty and to develop the orthosis for preventing the medial knee OA progress...

This study aimed to examine the effect of high tibial osteotomy (HTO) on the ankle and subtalar joints via analysis of static radiographic alignment. We hypothesised that surgical alteration of the alignment of the proximal tibia would result in compensatory distal changes.35 patients recruited as part of the wider Biomechanics and Bioengineering Centre Versus Arthritis HTO study between 2011 and 2018 had pre- and postoperative full-length weightbearing radiographs taken of their lower limbs. In addition to standard alignment measures of the limb and knee (mechanical tibiofemoral angle, Mikulicz point, medial proximal tibial angle), additional measures were taken of the ankle/subtalar joints (lateral distal tibial angle, ground-talus angle, joint line convergence angle of the ankle) as well as a novel measure of stance width. Results were compared using a paired T-test and Pearson's correlation coefficient.Following HTO, there was a significant (5.4°) change in subtalar alignment. Ground-talus angle appeared related both to the level of malalignment preoperatively and the magnitude of the alignment change caused by the HTO surgery; suggesting subtalar positioning as a key adaptive mechanism. In addition to compensatory changes within the subtalar joints, the patients on average had a 31% wider stance following HTO. These two mechanisms do not appear to be correlated but the morphology of the tibial plafond may influence which compensatory mechanisms are employed by different subgroups of HTO patients.These findings are of vital importance in clinical practice both to anticipate potential changes to the ankle and subtalar joints following HTO but it could also open up wider indications for HTO in the treatment of ankle malalignment and osteoarthritis.

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increased pain [6.2 (95%CI: 0.2, 12.3)], and VL in asymptomatic participants only [6.2 (95%CI: 2.2, 10.2)].Conclusions: Despite varied pain responses, all participants had reduced quadriceps and hamstring activation after a bout of physical activity. However, individuals with knee osteoarthritis who experienced increased pain had higher neuromuscular activation for all muscle groups before and after walking. Muscle strength was similar between groups, which may indicate higher co-activity of the quadriceps and hamstrings as a potential guarding mechanism to increase joint stiffness, reduce pain and possibly counterbalance joint instability. These preliminary results suggest that a bout of physical activity can reduce neuromuscular activation in quadriceps and hamstrings, however, pain levels as well as the pain response to physical activity must be considered during prescription.