Jesse M. Charlton

The effects of shoe-worn insoles on gait biomechanics in people with knee osteoarthritis: a systematic review and meta-analysis

Objectives The effect of shoe-worn insoles on biomechanical variables in people with medial knee osteoarthritis has been studied extensively. The majority of research has focused specifically on the effect of lateral wedge insoles at the knee. The aim of this systematic review and meta-analysis was to summarise the known effects of different shoe-worn insoles on all biomechanical variables during level walking in this patient population to date. Methods Four electronic databases were searched to identify studies containing biomechanical data using shoe-worn insole devices in the knee osteoarthritis population. Methodological quality was assessed and a random effects meta-analysis was performed on biomechanical variables reported in three or more studies for each insole. Results Twenty-seven studies of moderate-to-high methodological quality were included in this review. The primary findings were consistent reductions in the knee adduction moment with lateral wedge insoles, although increases in ankle eversion with these insoles were also found. Conclusion Lateral wedge insoles produce small reductions in knee adduction angles and external moments, and moderate increases in ankle eversion. The addition of an arch support to a lateral wedge minimises ankle eversion change, and also minimises adduction moment reductions. The paucity of available data on other insole types and other biomechanical outcomes presents an opportunity for future research.

Respiratory Mechanical and Cardiorespiratory Consequences of Cycling with Aerobars

Purpose Aerobars place a cyclist in a position where the trunk is flexed forward and the elbows are close to the midline of the body. This position is known to improve cycling aerodynamics and time trial race performance compared with upright cycling positions. However, the aggressive nature of this position may have important cardiorespiratory and metabolic consequences. The purpose of this investigation was to examine the respiratory mechanical, ventilatory, metabolic, and sensory consequences of cycling while using aerobars during laboratory-based cycling. Methods Eleven endurance-trained male cyclists (age, 26 ± 9 yr; V˙O2peak, 55 ± 5 mL·kg−1·min−1) were recruited. Visit 1 consisted of an incremental cycling test to determine peak power output. Visit 2 consisted of 6-min bouts of constant load cycling at 70% of peak incremental power output in the aerobar position, drop position, and upright position while grasping the brake hoods. Metabolic and ventilatory responses were measured using a commercially available metabolic cart, and respiratory pressures were measured using an esophageal catheter. Results Cycling in the aerobar position significantly increased the work of breathing (Wb), power of breathing (Pb), minute ventilation, ventilatory equivalent for oxygen and carbon dioxide, and transdiaphragmatic pressure compared with the upright position. Increases in the Wb and Pb in the aerobars relative to the upright position were strongly correlated with the degree of thoracic restriction, measured as the shoulder-to-aerobar width ratio (Wb: r = 0.80, P = 0.01; Pb: r = 0.69, P = 0.04). Conclusions Aerobars significantly increase the mechanical cost of breathing and leads to greater ventilatory inefficiency compared with upright cycling. Future work is needed to optimize aerobar width to minimize the respiratory mechanical consequences while optimizing aerodynamics.

The effects of a heel wedge on hip, pelvis and trunk biomechanics during squatting in resistance trained individuals.

Abstract Charlton, JM, Hammond, CA, Cochrane, CK, Hatfield, GL, and Hunt, MA. The effects of a heel wedge on hip, pelvis, and trunk biomechanics during squatting in resistance trained individuals. J Strength Cond Res 31(6): 1678–1687, 2017—Barbell back squats are a popular exercise for developing lower extremity strength and power. However, this exercise has potential injury risks, particularly to the lumbar spine, pelvis, and hip joint. Previous literature suggests heel wedges as a means of favorably adjusting trunk and pelvis kinematics with the intention of reducing such injury risks. Yet no direct biomechanical research exists to support these recommendations. Therefore, the purpose of this study was to examine the effects of heel wedges compared with barefoot on minimally loaded barbell back squats. Fourteen trained male participants performed a barbell back squat in bare feet or with their feet raised bilaterally with a 2.5-cm wooden block while 3-dimensional kinematics, kinetics, and electromyograms were collected. The heel wedge condition elicited significantly less forward trunk flexion angles at peak knee flexion, and peak external hip joint moments (p ⩽ 0.05) compared with barefoot conditions. However, no significant differences were observed between conditions for trunk and pelvis angle differences at peak knee flexion (p > 0.05). Lastly, no peak or root mean square differences in muscle activity were elicited between conditions (p > 0.05). Our results lend support for the suggestions provided in literature aimed at using heel wedges as a means of reducing excessive forward trunk flexion. However, the maintenance of a neutral spine, another important safety factor, is not affected by the use of heel wedges. Therefore, heel wedges may be a viable modification for reduction of excessive forward trunk flexion but not for reduction in relative trunk-pelvis flexion during barbell back squats.Barbell back squats are a popular exercise for developing lower extremity strength and power. However, this exercise has potential injury risks, particularly to the lumbar spine, pelvis and hip joint. Previous literature suggests heel wedges as a means of favourably adjusting trunk and pelvis kinematics with the intention of reducing such injury risks. Yet no direct biomechanical research exists to support these recommendations. Therefore, the purpose of this study was to examine the effects of heel wedges compared to barefoot on minimally loaded barbell back squats. Fourteen trained male participants performed a barbell back squat in bare feet or with their feet raised bilaterally with a 2.5cm wooden block while 3D kinematics, kinetics and electromyograms were collected. The heel wedge condition elicited significantly less forward trunk flexion angles at peak knee flexion, and peak external hip joint moments (p<0.05) compared to barefoot conditions. However, no significant differences were observed between conditions for trunk and pelvis angle differences at peak knee flexion (p>0.05). Lastly, no peak or root mean square differences in muscle activity were elicited between conditions (p>0.05). Our results lend support for the suggestions provided in literature aimed at utilizing heel wedges as a means of reducing excessive forward trunk flexion. However, the maintenance of a neutral spine, another important safety factor, is not affected by the use of heel wedges. Therefore, heel wedges may be a viable modification for reduction of excessive forward trunk flexion, but not for reduction in relative trunk-pelvis flexion during barbell back squats.

Ankle joint and rearfoot biomechanics during toe-in and toe-out walking in people with medial compartment knee osteoarthritis

Toe‐in and toe‐out walking are 2 strategies that have been shown to be effective in reducing the knee adduction moment in people with knee osteoarthritis. However, despite a positive biomechanical impact on the knee, altering foot rotation may impart unintended forces or joint positions on the ankle that could impact joint health. The kinematic and kinetic changes at the ankle during toe‐in or toe‐out walking have yet to be examined.

Toe-in and toe-out walking require different lower limb neuromuscular patterns in people with knee osteoarthritis

Toe-in and toe-out gait modification has received attention lately as a promising treatment for knee osteoarthritis due to its potential to improve knee joint loading and pain. However, the neuromuscular patterns associated with these walking styles are not well known, a factor that may influence knee joint load itself. Our aim was to conduct a thorough examination of the neuromuscular patterns associated with toe-in and toe-out walking in people with knee osteoarthritis. Fifteen participants were instructed to walk in four different foot rotations: 10° toe-in, 0°, as well as 10° and 20° toe-out. Nine surface electrodes were placed over lower extremity muscles and a variety of muscle activation parameters were examined. Peak and average medial hamstrings muscle activation was increased (p = 0.001, p < 0.001) during toe-in walking compared to toe-out walking. As well, average lateral gastrocnemius muscle activation was higher (p = 0.001) during toe-in walking compared to 20° toe-out. Medial thigh muscle co-contraction was higher (p = 0.003) during toe-in walking compared to all other conditions, and medial to lateral gastrocnemius activation ratio was lower (p = 0.032) during toe-in walking. These findings suggest potential overall increased joint loading with toe-in walking as a result of muscle co-contraction. Long-term assessment of these strategies is warranted.

Contralateral limb foot rotation during unilateral toe-in or toe-out walking in people with knee osteoarthritis

BACKGROUND Gait modification is a treatment approach often used for a variety of neuromuscular and musculoskeletal pathologies. Gait modification is commonly applied to a single limb, as is done with foot rotation (FR) in people with knee osteoarthritis (KOA). However, the extent to which gait changes observed in the trained limb are also exhibited in the untrained, contralateral limb during a training session is unknown. RESEARCH QUESTION The purpose of this study was to examine the within-limb FR differences across four unilateral FR modifications compared to natural walking. METHODS Sixteen individuals with KOA walked on a treadmill while performing four different FR conditions: 10° toe-in, 0°, 10° toe-out and 20° toe-out. Motion capture was conducted to track FR magnitude after five minutes of practice. RESULTS The change in contralateral FR angle compared to natural walking significantly increased during toe-in 10° walking (3.1°) compared to toe-out -10° and -20° walking (-1.2° and -1.5°, respectively). As expected, the ipsilateral FR angle was significantly different between all conditions. SIGNIFICANCE These results suggest that small, but statistically significant changes in the untrained contralateral limb FR are observed during FR training of the ipsilateral limb. This may indicate a desire for symmetry, or a compensation when modifying the ipsilateral limb. Therefore, clinicians may need to maintain baseline FR magnitudes in the untrained limb when a patient exhibits unilateral KOA characteristics or lateral compartment KOA.

Is quality of life reduced in people with patellofemoral osteoarthritis and does it improve with treatment? A systematic review, meta-analysis and regression

Abstract Purpose: To determine if quality of life is reduced in individuals with patellofemoral osteoarthritis, whether it can be improved with treatment, and potential factors associated with quality of life in individuals with patellofemoral osteoarthritis. Materials and methods: Published articles were identified by using electronic and manual searches. Studies reporting quality of life in individuals with patellofemoral osteoarthritis relative to a comparator group (e.g., no osteoarthritis) and intervention studies reporting quality of life in patellofemoral osteoarthritis following treatment relative to baseline/control group were included. Results: Seventeen studies (seven cross-sectional, 10 intervention) were included in this systematic review. Relative to those without osteoarthritis, individuals with patellofemoral osteoarthritis had worse knee-related quality of life (five studies) and health-related quality of life (two studies). Non-surgical treatments appear to improve knee-related quality of life compared to pre-treatment (three studies) but not control (three studies). Surgical-treatments also improved knee-related quality of life compared to pre-treatment (five studies). Worse knee-related quality of life was associated with younger age, worse pain, symptoms, function in activities of daily living, and function in sport and recreation. Conclusions: Individuals with patellofemoral osteoarthritis had worse knee-related and health-related quality of life compared to those without knee osteoarthritis. Non-surgical and surgical interventions may be effective in improving knee-related quality of life in individuals with patellofemoral osteoarthritis, but the intervention results are based on limited studies, and further research is needed to determine optimal strategies. Implications for rehabilitation Clinicians and researchers should consider knee-related and health-related quality of life when developing treatment strategies for patellofemoral osteoarthritis. Researchers investigating the effectiveness of a treatment should compare intervention to a control group. Addressing knee pain and functional limitations may aid in improving knee-related quality of life in individuals with patellofemoral osteoarthritis.

The Biomechanical Demands on the Hip During Progressive Stepping Tasks

Abstract Hatfield, GL, Charlton, JM, Cochrane, CK, Hammond, CA, Napier, C, Takacs, J, Krowchuk, NM, and Hunt, MA. The biomechanical demands on the hip during progressive stepping tasks. J Strength Cond Res 31(12): 3444–3453, 2017—Functional hip strengthening exercises are important components of lower extremity (LE) rehabilitation and include single-leg squats (SLS), step-downs (SD), and step-ups (SU). The biomechanical demand of these tasks is unclear. This repeated-measures study determined hip biomechanical demands in a healthy population. Twenty individuals (10 men, 26.6 ± 5.1 years, 22.1 ± 2.3 kg·m−2) participated. Three-dimensional motion, ground reaction force data, and surface electromyograms (EMG) were recorded during 4 randomly ordered tasks. Outcomes included frontal and sagittal plane hip moment impulses and muscle activity for each task. Repeated measures analysis of variance models (alpha = 0.05) determined between-task differences. Step-down and SLS were most biomechanically demanding, with significantly higher hip flexion and adduction moment impulses, and gluteus medius (GM) and quadriceps activity compared with half step-down (HSD) and SU. No significant difference was found between SD and SLS, indicating minimal difference in demand between the 2 tasks, likely due to kinematic similarities in performance; there were no significant differences in knee or hip sagittal plane angle excursion, or peak pelvic obliquity angle between the 2 tasks. Step-up was least demanding, with the lowest hip flexion and adduction moment impulses and GM, quadriceps, and hamstrings activity. Step-up was least demanding on the hip and would be a good starting task for hip strengthening protocols. Step-down and SLS were most demanding, requiring higher hip moments and muscle activity. These results provide evidence, which may be used in planning of progressive rehabilitation programs for patients with LE pathologies.