Gait Differences between Patients with Primary and Secondary Knee Osteoarthritis and the Impact on Disease Progression
Background: Different types of knee osteoarthritis (OA) exist. Primary knee OA may develop without a history of trauma. Secondary knee OA may develop after a traumatic injury. The way patients with knee OA walk influences how quickly the joint deteriorates and might play a role in disease development. However, gait patterns have not been compared between primary and secondary knee OA groups. The purpose is to investigate if knee mechanics and muscle activation during gait are risk factors for structural disease progression measured over 2 years with MRI and if these risk factors differ between primary and secondary knee OA.
Link to published article: DOI: 10.1016/j.joca.2019.02.798
Neuromuscular activation during gait in patients with Ehlers-Danlos syndrome and healthy adults
Objective: Ehlers-Danlos Syndrome (EDS) is a group of genetic disorders affecting the connective tissue and symptoms often include joint and ligament laxity. The objectives were to compare muscle activation, joint angles, and spatiotemporal parameters during gait, and isometric strength between participants with EDS (hypermobility and classical subtypes) and healthy adults. Methods: Participants with EDS (n=14) and healthy adults (n=14) were recruited for this cross-sectional study. Lower extremity muscle activation, sagittal joint angles, and spatiotemporal parameters during gait were measured using surface electromyography, motion capture, and force plates. Isometric strength of the lower extremity joints were measured with an isokinetic dynamometer. Important characteristics (principal components) were determined from electromyography and angle waveforms using principal component analysis; relationships between principal component scores and groups were examined using multilevel linear models, after accounting for gait speed. Spatiotemporal parameters and strength were compared using independent t-tests. Results: EDS group was associated with delayed vastus lateralis and medialis activation (p=0.01), higher rectus femoris (p=0.05) and tensor fascia latae (p=0.04) activation, prolonged gluteus medius activation (p=0.01), and lower medial gastrocnemius activation (p=0.02). Joint angles were similar between EDS and healthy groups. EDS group had slower gait speeds, shorter stride lengths, and greater percentage of time in stance (p<0.05). EDS group had weaker hip flexors, hip abductors, ankle plantarflexors, and ankle dorsiflexors (p<0.05). Conclusion: Alterations in muscle activation and spatiotemporal parameters during gait in patients with EDS may be a result impaired proprioception and balance, and muscle weakness. Interventions should target these deficits to improve functional movements.
Link to published article: https://doi.org/10.1002/acr.24067
Does Total Hip Arthroplasty Surgical Approach Affect Muscle Activation and Joint Mechanics during Gait
Objective: The lateral and posterior total hip arthroplasty (THA) surgical approaches are the most commonly used methods to perform a THA. The gluteus medius muscle is more disrupted during the lateral approach versus the gluteus maximus during the posterior approach. Impairments in these muscles following THA may impact lower extremity muscle activation, gait mechanics and physical function. Thus, the primary objective was to determine if lower extremity muscle activation patterns, joint angles and external hip moments during gait and isometric muscle torques differ between lateral and posterior approaches for THA one year after surgery and healthy adults. The secondary objective was to compare pain, physical function and spatio-temporal parameters one year after surgery between lateral and posterior THA approaches and healthy adults.
Link to published article: https://doi.org/10.1016/j.arth.2020.02.037
Mechanical and Muscular Demands of Lateral Trunk Lean Gait Patterns
Abstract: Lateral trunk lean (LTL) is a proposed intervention for knee osteoarthritis but increased muscular demands have not been considered. The objective was to compare lower extremity and trunk muscle activation and joint mechanics between normal and increased LTL gait in healthy adults. Participants (n=20, mean age 22 years) were examined under two gait conditions: normal and increased LTL. A motion capture system and force plates sampled at 100 and 2000Hz respectively were used to determine joint angles and external moments including LTL angle and external knee adduction moment (KAM). Surface electromyography, sampled at 2000Hz, measured activation of six trunk/hip muscles bilaterally. Peak LTL angle, peak KAM, gait speed, and mean values from electromyography waveforms were compared between normal and LTL conditions using paired t-tests or 2-way analysis of variance. There was a significant (p<0.05) increase in peak LTL angle, decrease in first but not second peak KAM, and decrease in gait speed during LTL gait. There were significant (p<0.01) increases in external oblique and iliocostalis muscle activation during LTL gait. There was no change in activation for internal oblique, rectus abdominis, longissimus, and gluteus medius. LTL gait decreased early/mid-stance KAM demonstrating its ability to decrease medial compartment knee loading. Increases in external oblique and iliocostalis activation were present but small to moderate in size and unlikely to lead to short term injury. Longitudinal studies should evaluate the effectiveness of increased LTL for knee osteoarthritis and if the increase in muscular demands leads to negative long term side effects.
Link to published article: https://doi.org/10.1016/j.gaitpost.2016.07.017