Utilising electrodermal activity sensor signals to quantify nociceptive response during movement activities.

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. The application of the stimuli resulted in a significant average increase (p < 0.05) in mean SC in four out of five activities with significant gender differences (p < 0.05) in SC and self-reported pain scores and large effect sizes. 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 could be utilised in a protocol that quantifies nociceptive response clinically meaningfully.

Using musculoskeletal modelling to estimate knee joint loading pre and post high tibial osteotomy.

BACKGROUND: Both medial knee osteoarthritis and associated varus alignment have been proposed to alter knee joint loading and consequently overloading the medial compartment. Individuals with knee osteoarthritis and varus deformity are candidates for coronal plane corrective surgery, high tibial osteotomy. This study evaluated knee loading and contact location for a control group, a pre-surgery cohort and the same cohort 12 months post-surgery using a musculoskeletal modelling approach. METHODS: Joint kinematics during gait were measured in 30 knee osteoarthritis patients, before and after high tibial osteotomy, and 28 healthy adults. Using a musculoskeletal model that incorporated patient-specific mechanical tibial femoral angle, the resulting muscle, ligament, and contact forces were calculated and the medial - lateral condyle load distribution was analysed. FINDINGS: Surgery changed medial compartment contact force throughout stance relative to pre-surgery. This reduction in medial compartment contact force pre- vs post-HTO is observed despite a significant increase in post-surgery walking speed compared to pre-HTO, where increased speed is typically associated with increased joint loading. INTERPRETATION: This study has estimated the effects of high tibial osteotomy on knee loading using a generic model that incorporates a detailed knee model to better understand tibiofemoral contact loading. The findings support the aim of surgery to unload the medial knee compartment and lateralise joint contact forces.

Does Gait Retraining Have the Potential to Reduce Medial Compartmental Loading in Individuals With Knee Osteoarthritis While Not Adversely Affecting the Other Lower Limb Joints? A Systematic Review.

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.