MECHANICAL PROPERTIES OF THE ACHILLES TENDON IN RUNNERS WITH TENDINOPATHY: A PILOT STUDY

The aim of this study was to compare the dimensions of Achilles tendon, Achilles tendon moment arm and foot lever ratio between runners with tendinopathy and healthy control runners. We paired 12 runners diagnosed with baseline tendinopathy with 12 healthy control runners. The dimensions of Achilles tendon, Achilles tendon moment arm and foot lever ratio were measured using kinematic analysis and ultrasound imaging. Based on the parametric paired-samples T-Test, we compared the dependent variables measured on the affected lower limb. No differences were found between the groups for Achilles tendon length, Achilles tendon moment arm and foot lever ratio. Runners diagnosed with tendinopathy had thicker Achilles tendons than healthy control runners

THE RELATIONSHIP BETWEEN ACHILLES TENDON DIMENSIONS AND FOOT STRIKE INDEX IN REARFOOT AND NON-REARFOOT RUNNERS

The purpose of this study was to describe the relationship between Achilles tendon dimensions and foot strike index in rearfoot and non-rearfoot runners. 107 recreational runners were divided into a group of rearfoot (n = 88) and a group of non-rearfoot runners (n = 19). Achilles tendon dimensions were measured by a combination of ultrasonography imaging and kinematic analysis. To analyse the footfall pattern, each participant performed 8 successful trials of running at their stated self-preferred endurance speed. Partial correlation was used for statistical analysis. Runners in the group of non-rearfoot runners, whose footfall pattern is more over forefoot, have a longer and thinner Achilles tendon

ASSOCIATION BETWEEN T2* RELAXATION TIME AND THE MECHANICAL PARAMETERS OF THE ACHILLES TENDON IN TRAINED AND UNTRAINED POPULATIONS: PRELIMINARY DATA

The purpose of this study was twofold: 1) to investigate the association between T2* relaxation time and Achilles tendon mechanical/material parameters (e.g., stiffness, Young’s modulus and hysteresis); and 2) to check the sensibility of the T2* in determining the differences among population, providing important insight for sports scientist and clinicians. Thirty participants (10 power athletes, 10 endurance athletes and 10 healthy participants) participated in this study. Magnetic resonance imaging (MRI) was used to quantify T2* relaxation time at rest. Ultrasound, kinetics, EMG and kinematics data were used to calculate Achilles tendon mechanical/material parameters during maximum voluntary contractions of the plantar-flexor muscles. Preliminary data on power athletes and healthy controls suggest that the Achilles tendon Young’s was higher in power athletes compared with healthy control, whereas tendon hysteresis and T2* relaxation time were lower in power athletes. Tendon stiffness was similar between populations. Our preliminary data suggest that T2* can be utilised to investigate the differences between the population in terms of material parameters (Young’s modulus and hysteresis) but not in mechanical ones (e.g. stiffness)

ELBOW AND WRIST JOINT LOADING IN GYMNASTICS: INJURY RISK IN ROUND OFF TECHNIQUE SELECTION

The aim of the current study was to investigate key elbow and wrist joint injury risk factors during different round-off (RO) techniques performed by young female artistic gymnasts. Ten active female gymnasts performed 30 successful trials of RO from a hurdle step with three different hand positions (parallel (10), T-shape (10) and reverse (10)). Synchronized kinematic and kinetic data were collected for each trial. One-way ANOVA and effect-size statistics determined differences between each hand position. Significant differences (p\u3c0.05 and large ES (\u3e0.8) among hand positions were found for peak VGRF, peak elbow and wrist compression force, and elbow internal adduction moment. Decrease in VGFR, elbow and wrist joint kinetics indicated that the T-shape technique may prevent elbow and wrist joint complex and reduces potential of injuries

TRENDELENBURG TEST AND ACL RISK FACTORS DURING UNANTICIPATED CUTTING MANOEUVRE – A PILOT STUDY

The aim of this study was to find differences between the Trendelenburg test and risk factors for an ACL injury during a cutting manoeuvre in two age groups. Six female athletes divided into two groups (n3x2) participated in this study. Ten infrared cameras and force platform were used to collect the kinematic and kinetic data. The results of this pilot study suggest no hip weakness was observed in either group. The younger group had a larger difference between starting and finishing position during TT. In other side we found the higher values of the ACL risk factors in the older group

Correlations between Achilles tendon material and structural properties and quantitative magnetic resonance imagining in different athletic populations

Achilles tendon stiffness (kAT) and Young's modulus (yAT) are important determinants of tendon function. However, their evaluation requires sophisticated equipment and time-consuming procedures. The goal of this study was twofold: to compare kAT and yAT between populations using the classical approach proposed in the literature (a combination of ultrasound and force data) and the MRI technique to understand the MRI's capability in determining differences in kAT and yAT. Furthermore, we investigated potential correlations between short and long T2* relaxation time, kAT and yAT to determine whether T2* relaxation time may be associated with material or structural properties. Twelve endurance and power athlete, and twelve healthy controls were recruited. AT T2* short and long components were measured using standard gradient echo MRI at rest, while kAT and yAT were evaluated using the classical method (combination of ultrasound and dynamometric measurements). Power athletes had the highest kAT (3064 ± 260, 2714 ± 260 and 2238 ± 189 N/mm for power athletes, endurance athletes and healthy control, respectively) and yAT (2.39 ± 0.28, 1.64 ± 0.22 and 1.97 ± 0.32 GPa for power athletes, endurance athletes and healthy control, respectively) and the lowest T2* short component (0.58 ± 0.07, 0.77 ± 0.06 and 0.74 ± 0.08 ms for power athletes, endurance athletes and healthy control, respectively). Endurance athletes had the highest T2* long component value. No correlations were reported between T2* long component, kAT or yAT in the investigated populations, whereas the T2* short component was negatively correlated with yAT. These results suggest that T2* short component could be used to investigate the differences in AT material properties in different populations

Running-related Achilles tendon injury: a prospective biomechanical study in recreational runners

There are relatively few running studies that have attempted to prospectively identify biomechanical risk factors associated with Achilles tendon (AT) injuries. Therefore, the aim was to prospectively determine potential running biomechanical risk factors associated with the development of AT injuries in recreational, healthy runners. At study entry, 108 participants completed a set of questionnaires. They underwent an analysis of their running biomechanics at self-selected running speed. The incidence of AT running-related injuries (RRI) was assessed after 1-year using a weekly questionnaire standardized for RRI. Potential biomechanical risk factors for the development of AT RRI injury were identified using multivariable logistic regression. Of the 103 participants, 25% of the sample (15 males and 11 females) reported an AT RRI on the right lower limb during the 1-year evaluation period. A more flexed knee at initial contact (odds ratio = 1.146, P = .034) and at the midstance phase (odds ratio = 1.143, P = .037) were significant predictors for developing AT RRI. The results suggested that a 1-degree increase in knee flexion at initial contact and midstance was associated with a 15% increase in the risk of an AT RRI, thus causing a limitation of training or a stoppage of running in runners

GENDER DIFFERENCES IN TECHNIQUE SELECTION: ELBOW AND WRIST JOINT LOADING DURING ROUND OFF IN GYMNASTICS

The aim of the study was to determine sex differences in the key elbow and wrist joint injury risk factors during different round-off (RO) techniques performed by young male and female gymnasts. Eight male and female young gymnasts performed 30 successful trials of RO with different hand positions (parallel [10], T-shape [10] and reverse [10]). Synchronized kinematic and kinetic data were collected for each trial. Two-way repeated measures ANOVA (3×2, technique×sex) and effect-size (ES) were used for statistical analysis. Risk factors including peak vertical ground reaction forces (VGRF), elbow and wrist compression forces, elbow internal adduction moments and elbow extension suggest that a RO in reverse and parallel techniques can be hazardous especially for young female gymnasts compared to male

FOOTFALL PATTERN IS NOT ASSOCIATED WITH ALTERED ACHILLES TENDON T2* RELAXATION TIME OF RECREATIONAL DISTANCE RUNNERS

Achilles tendon (AT) tendinopathy was reported to be the pathology with one of the highest incidences of all running-related injuries. Non-rearfoot FP has been proposed to be the risk factor for AT overload. T2* relaxation time of Achilles tendon is considered to be a marker of AT tendinopathy. Therefore, the purpose of this study was to compare T2* relaxation time of Achilles tendon (AT) between recreational runner population with rearfoot (RF) and non-rearfoot (NR) footfall patterns (FP). Twenty-two middle age recreational runners (11 rearfoot and 11 non-rearfoot), matched according to running distance, participated in this study. Resting T2* relaxation time was determined using a 1.5 Tesla magnetic resonance imaging technique. Lower extremity kinematics and kinetics were recorded during over-ground running at a self-selected speed. No significant differences were found between T2* relaxation time of the insertion portion of the AT between RF and NR runners. Structural properties of the most injured part of the AT is not affected by running FP in healthy middle-aged runners

Marker Placement Reliability and Objectivity for Biomechanical Cohort Study: Healthy Aging in Industrial Environment (Haie—Program 4)

In large cohort studies, due to the time-consuming nature of the measurement of movement biomechanics, more than one evaluator needs to be involved. This may increase the potential occurrence of error due to inaccurate positioning of markers to the anatomical locations. The pur-pose of this study was to determine the reliability and objectivity of lower limb segments length by multiple evaluators in a large cohort study concerning healthy aging in an industrial environment. A total of eight evaluators performed marker placements on five participants on three different days. Evaluators placed markers bilaterally on specific anatomical locations of the pelvis, thigh, shank and foot. On the right foot, markers were placed in anatomical locations to define a multi-segmental foot model. The position of the marker at the anatomical locations was recorded by a motion capture system. The reliability and objectivity of lower limb segment lengths was deter-mined by the intraclass correlation coefficient of a two-way random model and of the two-way mixed model, respectively. For all evaluators for all segments, the average reliability and objectivity was greater than 0.8, except for the metatarsus segment (0.683). Based on these results, we can con-clude that multiple evaluators can be engaged in a large cohort study in the placement of anatomical markers