COMPARISON OF ACCELEROMETRY STRIDE TIME CALCULATION METHODS

The purpose of this study was to investigate how a newly proposed method of stride time calculation, utilising data filtered at 2 Hz, compared to previous methods. Tibial accelerometry data for 6 participants completing half marathon running training were collected. One run was selected for each participant at random, from which five consecutive running strides were ascertained. Four calculation methods were employed to derive each stride time and results were compared. No significant difference was found between methods (p=1.00). The absolute difference in stride time, when comparing the proposed method to previous methods, ranged from 0.000 seconds to 0.039 seconds. Filtered data could offer a simplified technique for stride time output during running gait analysis, particularly when applied during automated data processing for large data sets

THE EFFECTS OF COMPRESSION SHORTS ON MUSCLE OSCILLATION AND LONG JUMP PERFROMANCE

Compression garments were used to explore their effect on athletic performance and muscle oscillation during a 3-step long jump task. The study consisted of a 3 dimensional kinematic analysis (Vicon Motus 9.2) with force data collected by a Kistler force platform. Ten male subjects performed 6 jumps under 2 conditions, bare leg (control condition) and with the compression shorts. Two-tailed paired samples T-test were conducted to discover significant changes in the measures of Muscle Oscillation (MO), Peak Vertical Ground Reaction Force (PVGRF), Peak Horizontal Ground Reaction Force (PHGRF) and Jump Length. The findings of the study suggest that long jump performance can be increased (.18m) while wearing compression shorts, although the legs ability to disperse force may be reduced by the garment

ACUTE EFFECTS OF OUTDOOR SURFACES ON RUNNING GAIT SYMMETRY AND REGULARITY ASSESSED BY TRUNK ACCELEROMETRY

The purpose of this study was to investigate if trunk accelerometry measures were influenced by outdoor surface while running. A sample of highly-trained (n=12) and recreational (n=17) ran on three independent surfaces, namely asphalt, synthetic track, and wood-chip. Dependent accelerometry measures were step frequency (SFREQ), step symmetry (SSYM), stride regularity (SREG), axis contribution to total amplitude (RMSRATIO) and sample entropy (SEN). Surface effects on accelerometry measures were consistent for both running groups. Several significant differences existed between wood-chip and either asphalt or synthetic track. The results suggest that surface specific considerations should be made when quantifying trunk accelerometry measures related to running gait symmetry and regularity during running

INVESTIGATION OF ATM PROPULSION FORCE-TIME PROFILES USING FUNCTIONAL DATA ANALYSIS ON FRONT CRAWL SPRINT SWIMMERS

The purpose of this investigation was to assess whether characteristics of the Assisted Towing Method (ATM) propulsive force-time profiles can discriminate between elite and sub-elite male sprint swimmers. Eleven elite and seven sub-elite sprint front crawl swimmers completed the ATM protocol to capture propulsion force-time profiles. The second full stroke cycle taken from the median propulsion trial on both the right and left arms were selected and functional data analysis was used to process the trials. Functional principal components analysis (fPCA) results revealed a statistical difference between the elite and sub-elite groups (p > 0.000). Further, within the elite group profiles, a distinctive double peak was found. The double peak profile could suggest a more efficient and effective stroking ratio of active drag and propulsion within the elite group

THE RELATIONSHIP BETWEEN ANKLE LAXITY AND FRONTAL PLANE ANGLES DURING NETBALL SPECIFIC TASKS: A PILOT STUDY

Ankle sprains are common in netball and, if quantified mechanical ankle laxity can be linked with ankle kinematics during common netball landing tasks, then preventative measures can be implemented to reduce the occurrence of such injuries. Four netball players had their ankle laxity measured with an ankle arthrometer and performed two landing tasks (a cutting manoeuvre and a linear running task involving a ball catch and sudden stop) within the 3D motion analysis laboratory. The participant with the highest arthrometry measured ankle laxity angle displayed the highest frontal plane range of motion during both landing tasks. A high correlation coefficient (R2=0.84) was found when comparing arthrometry measures with frontal plane range of motion during the cutting task. Although a promising relationship was observed, larger sample sizes are needed for more conclusive results

DOES SIDE OF AMPUTATION AFFECT 200- AND 400-M RACE TIME IN SPRINTERS USING RUNNING-SPECIFIC PROSTHESES?

Current Paralympic guidelines for track events are generally based on level of amputation, not side of amputation. Since 200- and 400-m sprint races are performed in a counter clockwise direction, the effects of amputations side on sprint race performance in athletes with unilateral lower limb amputation should be investigated. Forty-five unilateral transtibial amputees participating in elite-level 200- and 400-m races were analysed from publicly available Internet broadcasts. For each athlete, official race time, and amputation side were determined. We found no significant difference in official race time between left and right side amputees during the 200- and 400-m sprint, indicating that sprint performance on a standard track in amputee athletes is not affected by amputation side

DOES THE SITTING POSITION INFLUENCE CLAY TARGET SHOOTING PERFORMANCE IN ATHLETES WITH A MOTOR IMPAIRMENT?

Olympic trap clay target shooting (CTS) is currently performed by motor impaired individuals (MII), but not yet included in the International Paralympic Committee endorsement. This study aimed at supporting the development of a classification model that divides athletes competing in standing and sitting postures. Two groups of 5 standing and 5 sitting MII athletes were recruited for an instrumented CTS task execution. During competition, sitting athletes showed a lower rate of success with respect to the standing ones only for targets requiring wider ranges of motion, possibly due to fatigue. Their predominant use of upper body movements implies an adapted technique to reach a good performance, testified by a smoother movement, a lower peak accelerations at the gun tip, a smaller range for all absolute and relative rotations, and a different muscle activity

COMPARISON OF KINEMATIC PARAMETERS OF GAIT IN TRANSFEMORAL AMPUTEES WITH BIONIC AND HYDRAULIC KNEE – CASE STUDY

The development of new technologies has led to further improvements in prosthetic knee joints. The aim of this study was to compare kinematics in knee and hip joints during the gait of transfemoral amputees and to determine the effect of the type of knee joint used (bionic, hydraulic) on their symmetry. One female with transfemoral amputation participated in the study. Symmetry of lower limb movement in the hip joint is better for all monitored parameters for bionic knee joints. Flexion at heel contact and maximum flexion in the swing phase in the knee joint are more symmetrical at hydraulic knee joints; for all other parameters the bionic knee joints achieves better symmetry. Kinematics parameters in bionic knee amputees approximate to the parameters of gait in people without pathology

A CALIBRATION PROCEDURE FOR MIMU SENSORS ALLOWING FOR THE CALCULATION OF ELBOW ANGLES

Non-optical wearable sensors such as magnetic and inertial measurement units (MIMUs) are gaining popularity in sport and clinical settings owing to their ease of application, relative affordability and potential for improved ecological validity. We propose a method for the standardised reference calibration of a simple two-sensor MIMU system for the estimation of anatomically meaningful elbow kinematics. The participant poses with the elbow at 90° flexion and neutral (0°) pronation, allowing for the relative orientation of the MIMU on the forearm to be determined with reference to the MIMU located on the arm. Comparisons were with traditional kinematic marker method results. Root mean squared errors of less than 1° in flex/ext and < 2° (pro/sup) found in simple movements. Results with simple movements provide rationale to expand research to complex movements

OPTIMAL PATHWAY IN INNER LANE CURVING DURING MAXIMAL EFFORT SPRINT SPEED SKATING

The purpose of this study was to investigate experimentally the optimal pathway in the inner lane curving during maximal effort sprint skating with reference to changes in skating speed and crossover cycle motion for three different types of pathway by using wide-range three-dimensional motion analysis. This study suggests that the optimal pathway to enter the first inner curve might be to pass through the center of a 4m-wide lane or across a slightly more outer position at the inflection point of the skating oval. Taking the recommended pathway, skaters would improve their crossover technique, especially for the left stroke, and their final lap time could be faster in spite of the disadvantage of the roundabout way