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Purpose: The purposes of this study were to construct a real-time acceleration gait analysis system equipped with software to analyse real-time trunk acceleration during walking and to examine the intra-rater and inter-rater reliabilities of the this system.Methods: This system has been comprised of an accelerometer, an acceleration amplifier, a transmitter, two foot switches, a receiver and a personal computer installed with the real-time acceleration analysis software. The acceleration signals received were analysed using the real-time acceleration analysis software, and gait parameters were calculated. The subjects were 20 healthy individuals and two raters. The intra-rater and inter-rater reliabilities of the measurement results obtained from this system were examined by performing intraclass correlation coefficients (ICC) and Bland–Altman analysis.Results: The intra-rater and inter-rater ICCs ranged from 0.61 to 0.92 in any gait parameters. In the Bland–Altman analysis, neither fixed nor proportional bias was found in any of the gait parameters.Conclusions: From the ICC and Bland–Altman analysis results, the gait measurement using this system clearly demonstrates that the intra-rater and inter-rater measurements had good reproducibility. Owing to this system, we can improve the clinical efficiency of gait analysis and gait training for physiotherapy.Implication for RehabilitationThis study focused on the advantage of a gait analysis method using an accelerometer and constructed a gait analysis system that calculates real-time gait parameters from trunk acceleration measurements during walking. The gait analysis using this system has good intra-rater and inter-rater reliabilities, and using this system can improve the clinical efficiency of gait analysis and gait training. [ABSTRACT FROM PUBLISHER]

Background: An increase in the knee adduction moment is one of the risk factors of medial knee osteoarthritis. This study examined the relationship between knee adduction moment and self-reported pain and disability. We also investigated the influence of pain on the relationships between knee adduction moment and gait performance and disability. Methods: Thirty-eight Japanese women with medial knee osteoarthritis participated in this study (66.37years (41–79years)). Gait analysis involved the measurement of the external knee adduction moment impulse in the stance duration and during 3 subdivisions of stance. The total, pain and stiffness, and physical function Japanese Knee Osteoarthritis Measure scores were determined. Findings: The pain and stiffness, physical function, and total scores were positively correlated with the knee adduction moment impulses in the stance duration, and initial and second double support interval, and single limb support interval. The knee adduction moment impulse during the stance duration was related to the pain and stiffness subscale and gait velocity. The pain and stiffness subscale was related to the physical function subscale. Interpretation: Our results suggest that increasing in the knee adduction moment impulse, a proxy for loading on the medial compartment of the knee, is related to increased pain during weight-bearing activities such as walking, thereby restricting walking performance and causing disability by reducing gait velocity. Thus, the reduction in the knee adduction moment impulse during gait may result in pain relief and may serve as a conservative treatment option with disease-modifying potential. [Copyright &y& Elsevier]

Lateral wedge insoles (LWIs) are prescribed for patients with medial knee osteoarthritis to reduce the external knee adduction moment (KAM). However, the biomechanical effects of LWIs are limited in some patients. The purpose of this study was to investigate whether the biomechanical effects of LWIs depend on individual foot alignment and to examine the relationship between change in KAM and changes in foot and ankle biomechanics when wearing LWIs. Twenty-one patients participated in this study. They were categorized into normal or abnormal foot groups based on the foot posture index (FPI). All patients were requested to perform a normal gait under barefoot and LWI conditions. A three-dimensional motion analysis system was used to record 1st and 2nd KAM, knee adduction angular impulse (KAAI), center of pressure displacement, and knee-ground reaction force lever arm. Furthermore, the foot and ankle frontal plane kinematic parameters were evaluated. The 1st KAM was significantly reduced under the LWI condition compared to that under the barefoot condition in the normal foot group. In contrast, there was no significant difference in 1st KAM between both conditions in the abnormal foot group. Decreased rear foot eversion strongly correlated with reduction in the 1st KAM in the normal foot group. These findings suggested that it is helpful to assess individual foot alignment to ensure adequate insole treatment for patients with medial knee osteoarthritis and that decreased rear foot eversion during the early stance phase is significantly involved in the reduction of 1st KAM when wearing LWIs with normal feet. [ABSTRACT FROM AUTHOR]

Background: During gait, the swing limb requires flexible control to adapt to ever changing environmental circumstances. However, few studies have focused on the mechanics of swing limb control in patients with knee osteoarthritis (OA). Investigating the variability of swing limb kinematics, which can be represented by variables such as the peak shank angular velocity during the swing phase obtained from an inertial sensor, provides insights into the adaptability of swing limb control. The purpose of this study was to investigate how patients with knee OA control the swing limb and whether the degree of impairment and disability due to knee OA affects swing limb control.Methods: Twelve subjects diagnosed with knee OA and 11 healthy control subjects participated in this study. Subjects walked on a treadmill for 10min. The mean, coefficient of variation, and fractal scaling exponent α of the peak shank angular velocity during the swing phase were calculated.Findings: There were no significant differences between the groups for any of the kinematic parameters. The Knee Injury and Osteoarthritis Outcome Score (KOOS) activities of daily living (ADL) subsection correlated with the coefficient of variation (r=-0.677, p=0.016) and the scaling exponent α (r=0.604, p=0.037) of the peak shank angular velocity.Interpretation: Control of the swing limb was associated with the degree of impairment and disability. Larger and more random variability of peak shank angular velocity may indicate decreased ADL ability in patients with knee OA. [ABSTRACT FROM AUTHOR]

Lateral wedge insoles (LWIs) reduce the peak external knee adduction moment (KAM). However, the efficacy of LWIs is limited in certain individuals for whom they fail to decrease KAM. Possible explanations for a lack of desired LWI response are variations in foot alignments. The purpose of this study was to evaluate whether the immediate biomechanical effects of LWIs depend on individual foot alignments during gait. Fifteen healthy adults participated in this study. Their feet were categorized as normal, pronated, and supinated using the foot posture index. All subjects were subsequently requested to perform a normal gait under barefoot and LWI conditions. A three-dimensional motion analysis system was used to record the kinematic and kinetic data, included peak KAM, KAM impulse (KAAI), center of pressure displacement, and knee-ground reaction force lever arm (KLA). Furthermore, lower limb frontal plane kinematic parameters at the rear foot, ankle, knee, and hip were evaluated. Among all feet, there was no significant difference in the peak KAM and KAAI between the conditions. In contrast, the peak KAM was significantly reduced under the LWI condition relative to the barefoot condition in the normal foot group. Reductions in the peak KAM were correlated with a more lateral center of pressure and reduced KLA. In addition, a reduced KLA was correlated with decreased hip adduction. LWIs significantly reduced the peak KAM in normal feet, indicating that biomechanical effects of LWIs vary between individual foot alignments. Our findings suggest that it is helpful to assess individual foot alignment to ensure adequate insole treatment for patients with knee osteoarthritis. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate the effects of cognitive and visuomotor tasks on gait control in terms of the magnitude and temporal structure of the variability in stride time and lower-limb kinematics measured using inertial sensors. Fourteen healthy young subjects walked on a treadmill for 15min at a self-selected gait speed in the three conditions: normal walking without a concurrent task; walking while performing a cognitive task; and walking while performing a visuomotor task. The time series data of stride time and peak shank angular velocity were generated from acceleration and angular velocity data recorded from both shanks. The mean, coefficient of variation, and fractal scaling exponent α of the time series of these variables and the standard deviation of shank angular velocity over the entire stride cycle were calculated. The cognitive task had an effect on long-range correlations in stride time but not on lower-limb kinematics. The temporal structure of variability in stride time became more random in the cognitive task. The visuomotor task had an effect on lower-limb kinematics. Subjects controlled their swing limb with greater variability and had a more complex adaptive lower-limb movement pattern in the visuomotor task. The effects of the dual tasks on gait control were different for stride time and lower-limb kinematics. These findings suggest that the temporal structure of variability and lower-limb kinematics are useful parameters to detect a change in gait pattern and provide further insight into gait control. [ABSTRACT FROM AUTHOR]