Competitive and Recreational Running Kinematics Examined Using Principal Components Analysis

Kinematics data are primary biomechanical parameters. A principal component analysis (PCA) of waveforms is a statistical approach used to explore patterns of variability in biomechanical curve datasets. Differences in experienced and recreational runners’ kinematic variables are still unclear. The purpose of the present study was to compare any differences in kinematics parameters for competitive runners and recreational runners using principal component analysis in the sagittal plane, frontal plane and transverse plane. Forty male runners were divided into two groups: twenty competitive runners and twenty recreational runners. A Vicon Motion System (Vicon Metrics Ltd., Oxford, UK) captured three-dimensional kinematics data during running at 3.3 m/s. The principal component analysis was used to determine the dominating variation in this model. Then, the principal component scores retained the first three principal components and were analyzed using independent t-tests. The recreational runners were found to have a smaller dorsiflexion angle, initial dorsiflexion contact angle, ankle inversion, knee adduction, range motion in the frontal knee plane and hip frontal plane. The running kinematics data were influenced by running experience. The findings from the study provide a better understanding of the kinematics variables for competitive and recreational runners. Thus, these findings might have implications for reducing running injury and improving running performance.

Lower limb biomechanics in individuals with chronic ankle instability during gait: a case-control study

Background Individuals with chronic ankle instability (CAI) exhibit many biomechanical changes to lower limbs during walking. However, only a few studies have investigated the differences in lower limb biomechanics of individuals with CAI compared to healthy controls using a comprehensive approach including kinematic, kinetic and electromyography (EMG) measures. Consequently, the theoretical framework explaining the biomechanical adaptations in individuals with CAI is mostly based on the results of studies including heterogenous methods and participants’ specificities (e.g., level of disability). More studies using a comprehensive approach are needed to better understand the biomechanical adaptations associated with CAI. The objective of this case-control study was to identify the kinematic, kinetic and EMG differences between individuals with CAI and healthy controls during walking. Methods Twenty-eight individuals with CAI and 26 healthy controls were recruited to walk at a self-selected speed during which lower limb kinematics, kinetics and EMG were analysed. Ankle and knee angles and moments as well as gluteus medius, vastus lateralis, gastrocnemius lateralis, peroneus longus and tibialis anterior muscles activity were compared between the CAI and control groups using one-dimensional statistical parametric mapping. Results The CAI group exhibited greater ankle inversion angles from 14 to 48% of the stance phase (%SP) (p = 0.008), ankle eversion moments from 40 to 78%SP (p < 0.001), knee abduction moments from 3 to 6%SP and peroneus longus muscle activity from 0 to 15%SP (p = 0.003) and 60 to 76%SP (p = 0.003) compared to the control group. No significant between-group differences in ankle sagittal and transverse angles and moments, knee angles, knee sagittal and transverse moments as well as gluteus medius, vastus lateralis, gastrocnemius lateralis and tibialis anterior muscles activity were found. Conclusions During the first half of the stance phase, individuals with CAI could be at more risk of sustaining recurrent LAS mostly due to greater ankle inversion angles. However, the greater ankle eversion moments and peroneus longus muscle activity during the second half of the stance phase were an efficient mechanism to correct this maladaptive gait pattern and allowed to attenuate the faulty ankle movements during the pre-swing phase.

CORRELATIONS BETWEEN PLANTAR PRESSURE AND JOINT KINEMATICS IN FEMALE RECREATIONAL RUNNERS

performed simultaneous assessments of plantar pressure and joint kinematics; however, they have not investigated correlations between these parameters. The goal of this study was to assess relationships between joint kinematics and plantar pressure metrics during stance phase of running. Fifteen female recreational runners participated in this study. Three-dimensional motion analysis and plantar pressure data were collected simultaneously as the subjects ran on an instrumented treadmill. Participants ran at a self-selected speed while maintaining a heart rate (HR) at 70-80% of their maximum HR (max HR = 220 – age). Sagittal and coronal plane motion of the ankle and hip and sagittal plane motion of the knee, along with peak plantar pressure, peak ground reaction force (GRF), force impulse, and pressure impulse were examined. Spearman rho correlation tests were performed to determine correlations among lower extremity joint kinematics and plantar pressure metrics. Positive correlations were found between peak plantar pressure and ankle dorsiflexion, knee flexion, and ankle inversion as well as between running speed and peak GRF. These correlations gave insight into risk factors for injury based on the relationship between plantar pressure metrics and joint kinematics.

Pure isolated medial talonavicular joint dislocation following low-energy trauma: a case report

Midtarsal dislocations are relatively rare injuries secondary to high-energy trauma and are typically accompanied by disruption of ligamentous structures and fractures of the midfoot. We herein present a case of a pure isolated medial swivel dislocation of the talonavicular joint (TNJ) that was sustained following low-energy trauma without an associated fracture. A 78-year-old woman visited our emergency department with severe pain in the midfoot area of the right foot without neurovascular deficits. She had sustained this injury after severe ankle inversion while going downstairs. Plain radiographs of the right foot showed that the navicular was dislocated medially on the talus; no other malalignments were present. Three-dimensional computed tomography revealed dislocation of the TNJ, but no other tarsal or midtarsal bone fractures or dislocations. A medial dorsal incision was made to expose the TNJ. The dorsal talonavicular ligament was ruptured and interposed between the navicular and talus. The ligament was removed and the TNJ was reduced. The clinical outcome at the 1-year follow-up was satisfactory with no limitations in daily activities. In summary, we have reported an extremely rare case of a pure isolated medial TNJ dislocation in which the interposed dorsal talonavicular ligament served as an obstacle to reduction.

People with chronic ankle instability benefit from brace application in highly dynamic change of direction movements

Background The application of ankle braces is an effective method for the prevention of recurrent ankle sprains. It has been proposed that the reduction of injury rates is based on the mechanical stiffness of the brace and on beneficial effects on proprioception and neuromuscular activation. Yet, how the neuromuscular system responds to the application of various types of ankle braces during highly dynamic injury-relevant movements is not well understood. Enhanced stability of the ankle joint seems especially important for people with chronic ankle instability. We therefore aimed to analyse the effects of a soft and a semi-rigid ankle brace on the execution of highly dynamic 180° turning movements in participants with and without chronic ankle instability. Methods Fifteen participants with functional ankle instability, 15 participants with functional and mechanical ankle instability and 15 healthy controls performed 180° turning movements in reaction to light signals in a cross-sectional descriptive laboratory study. Ankle joint kinematics and kinetics as well as neuromuscular activation of muscles surrounding the ankle joint were determined. Two-way repeated measures analyses of variance and post-hoc t-tests were calculated. Results Maximum ankle inversion angles and velocities were significantly reduced with the semi-rigid brace in comparison to the conditions without a brace and with the soft brace (p ≤ 0.006, d ≥ 0.303). Effect sizes of these reductions were larger in participants with chronic ankle instability than in healthy controls. Furthermore, peroneal activation levels decreased significantly with the semi-rigid brace in the 100 ms before and after ground contact. No statistically significant brace by group effects were found. Conclusions Based on these findings, we argue that people with ankle instability in particular seem to benefit from a semi-rigid ankle brace, which allows them to keep ankle inversion angles in a range that is comparable to values of healthy people. Lower ankle inversion angles and velocities with a semi-rigid brace may explain reduced injury incidences with brace application. The lack of effect of the soft brace indicates that the primary mechanism behind the reduction of inversion angles and velocities is the mechanical resistance of the brace in the frontal plane.