Muscle timing in injured and non-injured leg of athletes with chronic ankle instability in response to a visual stimulus during forward jumping

Kinematic Analysis of Human Gait in Healthy Young Adults Using IMU Sensors: Exploring Relevant Machine Learning Features for Clinical Applications

BACKGROUND

Gait is the manner or style of walking, involving motor control and coordination to adapt to the surrounding environment. Knowing the kinesthetic markers of normal gait is essential for the diagnosis of certain pathologies or the generation of intelligent ortho-prostheses for the treatment or prevention of gait disorders. The aim of the present study was to identify the key features of normal human gait using inertial unit (IMU) recordings in a walking test.

METHODS

Gait analysis was conducted on 32 healthy participants (age range 19-29 years) at speeds of 2 km/h and 4 km/h using a treadmill. Dynamic data were obtained using a microcontroller (Arduino Nano 33 BLE Sense Rev2) with IMU sensors (BMI270). The collected data were processed and analyzed using a custom script (MATLAB 2022b), including the labeling of the four relevant gait phases and events (Stance, Toe-Off, Swing, and Heel Strike), computation of statistical features (64 features), and application of machine learning techniques for classification (8 classifiers).

RESULTS

Spider plot analysis revealed significant differences in the four events created by the most relevant statistical features. Among the different classifiers tested, the Support Vector Machine (SVM) model using a Cubic kernel achieved an accuracy rate of 92.4% when differentiating between gait events using the computed statistical features.

CONCLUSIONS

This study identifies the optimal features of acceleration and gyroscope data during normal gait. The findings suggest potential applications for injury prevention and performance optimization in individuals engaged in activities involving normal gait. The creation of spider plots is proposed to obtain a personalised fingerprint of each patient's gait fingerprint that could be used as a diagnostic tool. A deviation from a normal gait pattern can be used to identify human gait disorders. Moving forward, this information has potential for use in clinical applications in the diagnosis of gait-related disorders and developing novel orthoses and prosthetics to prevent falls and ankle sprains.

Peroneal muscle activity during stable and unstable load exercises. A cross-sectional study

OBJECTIVE

To evaluate the muscle activity of the peroneus longus during the execution of different unstable load exercises compared to stable load exercises.

DESIGN

Cross-sectional study.

SETTING

Functional Anatomy Laboratory.

PARTICIPANTS

28 healthy athletes.

MAIN OUTCOME MEASURES

Surface electromyography (sEMG), unstable load (water tank), Stable Load (Sandbag), type of exercise (Isometric single leg stance, single-leg Romanian deadlift, front rack forward lunge and lateral lunge).

RESULTS

The repeated measures ANOVA revealed significant Group ∗ Time interaction in Root Mean Square (RMS) (F = 51.307, P < 0.001, ŋ² = 0.70). In the between-group analysis there were statistically significant differences in RMS isometric single leg stance in favor to unstable load (P < 0.001, ŋ² = 0.07). In the within-group analysis of RMS statistically significant differences were found in the stable load group between isometric single leg stance and single-leg Romanian deadlift (P < 0.001, ŋ² = 0.05).

CONCLUSIONS

Single leg stance exercise with unstable load showed higher peroneus muscle activity than stable load. However, no peroneus muscle activity differences were found between unstable and stable loads for single-leg Romanian deadlift, frontal rack forward lunge and lateral lunge. Single-leg Romanian deadlift with stable load showed higher peroneus muscle activity than isometric single leg stance with stable load.

THE RELATIONSHIP BETWEEN SINGLE LEG BALANCE AND ISOMETRIC ANKLE AND HIP STRENGTH IN A HEALTHY POPULATION

Background

Impaired balance and strength commonly affect athletes with conditions like chronic ankle instability (CAI). Yet, clinical research surrounding the relationship between balance, strength, and CAI is still growing. Deeper investigation of these relationships is warranted to better inform clinical practice patterns when managing athletes with balance deficits.

Purpose

To investigate the relationship between single leg balance, ankle strength, and hip strength in healthy, active adults.

Study Design

Observational study.

Methods

Forty healthy participants (age 23.7 ± 4.9 years) were assessed for static balance, using a modified version of the Balance Error Scoring System (mBESS), as well as isometric strength of ankle and hip musculature via handheld dynamometry. Pearson's correlations were used to analyze relationships between balance and strength measures. Paired t-tests were utilized to compare dominant and non-dominant limb performance.

Results

Negligible to low, negative correlations were found between balance scores and hip extension strength (r = -0.24 to -0.38, p<0.05). High, positive correlations were found between ankle and hip strength measures (r = 0.75 to 0.84, p<0.05). When comparing dominant to non-dominant limbs, only minimal differences were noted in ankle eversion strength (mean difference = 6.0%, p<0.01) and hip extension strength (mean difference = 5.5%, p<0.01).

Conclusions

Minimal relationships were identified between static balance and isometric ankle and hip strength. Comparison of dominant and non-dominant limbs suggests that clinicians should expect relative symmetry in balance and strength in healthy adults. Thus, asymmetries found during clinical examination should raise suspicion of specific impairments that may lead to dysfunction.

Level of Evidence

2c.

Reaction time and muscle activation patterns in elite and novice athletes performing a taekwondo kick

Fractionated reaction time can be used to determine distinct epochs known as pre-motor, response and movement times (MTs) of a reaction time task. The purpose of this study was to compare elite and novice athletes performing a taekwondo kick in terms of the fractionated reaction time and electromyography (EMG) activation patterns of the muscles of the striking lower limb and the lower back. We hypothesised that the pre-motor time, response time (RT) and MT would be the shorter for elite athletes compared to novices. We collected data on 13 elite and 10 novice athletes when performing a roundhouse kick. The experiment included EMG electrodes placed on five low back and lower extremity muscles and an electrogoniometer placed on the kicking knee. We found that pre-motor time was shorter and the RT was longer for elite athletes than novice athletes. Moreover, the integrated EMG of the main knee extensor does not differ between groups though other leg and trunk muscles do. The results allow coaches and teachers to understand this particular taekwondo kicking movement which could ultimately improve the technique in order to establish training and teaching goals.