Evaluation of multi-segmental kinematic modelling in the paediatric foot using three concurrent foot models

Background: Various foot models are used in the analysis of foot motion during gait and selection of the appropriate model can be difficult. The clinical utility of a model is dependent on the repeatability of the data as well as an understanding of the expected error in the process of data collection. Kinematic assessment of the paediatric foot is challenging and little is reported about multi-segment foot models in this population. The aim of this study was to examine three foot models and establish their concurrent test-retest repeatability in evaluation of paediatric foot motion during gait. Methods: 3DFoot, Kinfoot and the Oxford Foot Model (OFM) were applied concurrently to the right foot and lower limb of 14 children on two testing sessions. Angular data for foot segments were extracted at gait cycle events and peaks and compared between sessions by intraclass correlation coefficient (ICC) with 95% confidence intervals (95% CI) and standard error of measurement (SEM). Results: All foot models demonstrated moderate repeatability: OFM (ICC 0.55, 95% CI 0.16 to 0.77), 3DFoot (ICC 0.47, 95% CI 0.15 to 0.64) and Kinfoot (ICC 0.43, 95% CI −0.03 to 0.59). On the basis of a cut-off of 5°, acceptable mean error over repeated sessions was observed for OFM (SEM 4.61° ± 2.86°) and 3DFoot (SEM 3.88° ± 2.18°) but not for Kinfoot (SEM 5.08° ± 1.53°). Reliability of segmental kinematics varied, with low repeatability (ICC < 0.4) found for 14.3% of OFM angles, 22.7% of 3DFoot angles and 37.6% of Kinfoot angles. SEM greater than 5° was found in 26.2% of OFM, 15.2% of 3DFoot, and 43.8% of Kinfoot segmental angles. Conclusion: Findings from this work have demonstrated that segmental foot kinematics are repeatable in the paediatric foot but the level of repeatability and error varies across the segments of the different models. Information on repeatability and test-retest errors of three-dimensional foot models can better inform clinical assessment and advance understanding of foot motion during gait

Current Understanding of the Impact of Childhood Obesity on the Foot and Lower Limb

Childhood obesity has emerged in recent years as a major public health problem. As this continues to concern across local, national and international populations, and as our understanding of obesity advances, access to multi-disciplinary care and understanding of the complications is warranted. Recent findings have suggested that the musculoskeletal system is one of the multiple body systems compromised by obesity and that aberrant biomechanical function may be a precursor to the onset of musculoskeletal symptoms. This review will consider childhood obesity and its impact on the paediatric foot and lower limb through examination of literature on foot structure and biomechanics of gait. An overview of evidence-based management is out with the context of this review, however some recommendations for clinical practice will be proposed

Biomechanical characteristics of lower limb gait waveforms: Associations with body fat in children

Childhood obesity is associated with musculoskeletal dysfunction and altered lower limb biomechanics during gait. Few previous studies have explored relationships between childhood obesity measured by body fat and lower limb joint waveform kinematics and kinetics. What is the association between body fat and hip, knee and ankle joint angles and moments during gait and in 7 to 11 year-old boys? Fifty-five boys participated in the study. Body fat was measured by air displacement plethysmography. Hip, knee and ankle 3D waveforms of joint angles and moments were recorded during gait. Principle component analysis was used to reduce the multidimensional nature of the waveform into components representing parts of the gait cycle. Multiple linear regression analysis determined the association between the components with body fat. Higher body fat predicted greater hip flexion, knee flexion and knee internal rotation during late stance and greater ankle external rotation in late swing/early stance. Greater hip flexion and adduction moments were found in early stance with higher body fat. In mid-stance, greater knee adduction moments were associated with high body fat. Finally, at the ankle, higher body fat was predictive of greater internal rotation moments. The study presents novel information on relationships between body fat and kinematic and kinetic waveform analysis of paediatric gait. The findings suggest altered lower limb joint kinematics and kinetics with high body fat in young boys. The findings may help to inform research in to preventing musculoskeletal comorbidities and promoting weight management. [Abstract copyright: Copyright © 2018 Elsevier B.V. All rights reserved.

Biomechanics of the Paediatric Foot and Lower Limb during Gait: Associations with Obesity

Introduction Childhood obesity is associated with altered gait characteristics. However, little is understood about the impact of obesity on three-dimensional biomechanics of the paediatric foot and lower limb. The aim of this study was to examine the associations between foot and lower limb biomechanics and obesity in boys aged 7 to 11 years. Methods Fifty five boys (mean age 9.56 ± 1.13 years) were recruited. Each participant was measured for percentage body fat (%BF) by air displacement plethysmography (mean %BF 23.78 ± 9.33%, range 9.57 - 42.06%). Three-dimensional foot and lower limb motion was measured by an 8-camera motion capture system. Following reduction by principle component analysis, multilevel linear regression determined the association between biomechanical variables and body fat. Results Participants with higher %BF demonstrated greater hip, knee, ankle and midfoot flexion; ankle and midfoot eversion; ankle and rearfoot external rotation. Participants with higher %FM also demonstrated greater hip flexion and external rotation moments and, greater knee adduction moments. Conclusion Findings from this study support the view that obesity is associated with altered biomechanics of the foot and lower limbs during gait. Data from this study suggests obese children have a pronated foot type, a possible precursor to altered function and pathology in later years. Further work is required to understand the long term impact of altered foot motion during gait associated with childhood obesity

Concurrent Validity of Lower Limb Muscle Strength by Handheld Dynamometry in Children 7 to 11 Years Old

Context: The assessment of pediatric muscle strength is necessary in a range of applications, including rehabilitation programs. Handheld dynamometry (HHD) is considered easy to use, portable, and low cost, but validity to measure lower limb muscle strength in children has not been assessed. Objective: To determine the concurrent validity of lower limb torque from HHD compared with isokinetic dynamometry (ID) in children aged from 7 to 11 years old. Design: A descriptive assessment of concurrent validity of lower limb joint torques from HHD compared with ID. Methods: Sixty-one typically developing children underwent assessment of maximal hip, knee, and ankle isometric torque by HHD and ID using standardized protocols. Joint positions were selected to represent maximal strength and were replicated between devices. Concurrent validity was determined by Pearson correlation, limits of agreement, and Bland–Altman plots. Results: Correlations between HHD and ID were moderate to large for knee extension (r 95% CI, .39 to .73), small to large for plantar flexion (r 95% CI, .29 to .67), knee flexion (r 95% CI, .16 to .59), hip flexion (r 95% CI, .21 to .57), hip extension (r 95% CI, .18 to .54), and hip adduction (r 95% CI, .12 to .56), and small to moderate for dorsiflexion (r 95% CI, −.11 to .39) and hip abduction (r 95% CI, −.02 to .46). Limits of agreement for all joint torques were greater than 10% indicating large error in HHD measured torque compared with ID. A positive proportional bias was detected for plantarflexion, indicating that HHD underestimated torque to a greater extent in participants with higher torque values. Conclusions: Maximal torque values from HHD and ID are consistent with those previously reported in the literature. Poor concurrent validity of HHD may have arisen from issues around joint position, joint stabilization, and the experience of the tester to prevent an isokinetic contraction. Pediatric lower limb muscle strength assessed by HHD should be interpreted with caution

Concurrent Validity of Lower Limb Muscle Strength by Handheld Dynamometry in Children 7 to 11 Years Old

Context The assessment of pediatric muscle strength is necessary in a range of applications, including rehabilitation programmes. Hand-held dynamometry is considered easy to use, portable and low cost, but validity to measure lower limb muscle strength in children has not been assessed. Objective To determine the concurrent validity of lower limb torque from hand-held dynamometry (HHD) compared to isokinetic dynamometry (ID) in children age 7 to 11 years old. Design A descriptive assessment of concurrent validity of lower limb joint torques from HHD compared to ID. Methods Sixty-one typically developing children underwent assessment of maximal hip, knee and ankle isometric torque by HHD and ID using standardized protocols. Joint positions were selected to represent maximal strength and were replicated between devices. Concurrent validity was determined by Pearson’s correlation, limits of agreement, and Bland-Altman plots. Results Correlations between HHD and ID were moderate-to-large for knee extension (r 95%CI: 0.39 to 0.73), small-to-large for plantarflexion (r 95%CI: 0.29 to 0.67), knee flexion (r 95%CI: 0.16 to 0.59), hip flexion (r 95%CI: 0.21 to 0.57), hip extension (r 95%CI: 0.18 to 0.54), and hip adduction (r 95%CI: 0.12 to 0.56), and small-to-moderate for dorsiflexion (r 95%CI: -0.11 to 0.39) and hip abduction (r 95%CI: -0.02 to 0.46). Limits of Agreement for all joint torques were greater than 10% indicating large error in HHD measured torque compared to ID. A positive proportional bias was detected for plantarflexion, indicating that HHD underestimated torque to a greater extent in participants with higher torque values. Conclusions Maximal torque values from HHD and ID are consistent with those previously reported in the literature. Poor concurrent validity of HHD may have arisen from issues around joint position, joint stabilization and the experience of the tester to prevent an isokinetic contraction. Pediatric lower limb muscle strength assessed by hand-held dynamometry should be interpreted with caution