The Effect of Increasing Running Speed on Mechanical Work of the Lower Limbs in Elite Male Runners

Introduction: Understanding the biomechanical performance of the lower limb joint during running is of the utmost importance for enhancing our current understanding of high human performance, as well as for identifying potential factors that may be associated with injuries. Given that the mechanical work of the lower limb joints conveys crucial information about joint function, the objective of the present study was to examine the impact of increasing running speed on the mechanical work of elite male runners. Materials and Methods: The current study is an observational cross-sectional study.28 healthy male elite runners aged 22 - 51 years ran on a treadmill with a force plate in the middle of the walk-way, at three different speeds, 2.5, 3.5 and 4.5 m/s respectively, and the data related to the mechanical work of the lower limbs were recorded and extracted. Also, in order to compare the averages of the Hip, Knee and Ankle mechanical work variables, ANOVA repeated measurements method with Bonferroni post hoc test was used. Results: It was found that increasing the speed leads to a significant difference in the mechanical work of the joints of the lower limbs including hip and ankle in both absorption and production phases(P<0.05) except in the knee joint at a speed of 3.5 to 4.5 in positive mechanical work (P=0.121). Conclusion: Considering the biomechanics of running is very important as a basic skill that every person performs during his life. The mechanical work aspects of the hip, knee, and ankle joints during increased running speed may potentially provide a biomechanical explanation for these clinical observations

Shoulder Injuries in Sport: A Systematic Review

ABSTRACT Background: The purpose of this study was to, present and discuss the accumulated knowledge involvement in various shoulder injuries and highlight the clinical implications for the evaluation and treatment of shoulder injuries. Shoulder injuries are common in both athletes and non-athletes. Risk factors for shoulder injuries are unknown despite the increase in injury rates. We seek to summarize the causes of shoulder injuries in athletes. Study Design: Systematic review. Methods: Searches were performed on 4 databases using keywords related to shoulder injury factors and a review of all applicable manuscripts was performed. Result: Ninety-three articles met criteria for inclusion. Of the all independent variables that were analyzed, age, overhead throw sport and other sport, professional or amateur, contact and non-contact sports, male and female and related fall in sports were found to be independent risk factors for shoulder injuries. Conclusion: The comparison of sport to non-sport shoulder injury incidence rates suggests that the increased risk of shoulder injuries in young males is mainly attributable to sports injuries. Men are more exposed to upper limb injuries

Three Planar Symmetry of Hip, Knee and Ankle Joints’ Moments during Running: Three planar Symmetry of Hip, Knee and Ankle Joints’ moments during Running

Introduction: Symmetry and asymmetry of the limbs’ movement pattern during running are introduced as one of the main critical challenges of human locomotion. The aim of this study was to investigate three planar symmetry of hip, knee and ankle joints’ moments during running at a fixed speed. Methods and Materials: the present study was conducted as a quasi-experimental study. Elite runner (age: 34.75±6.63 years) participated in this study. Running at constant speed was conducted by each subject at 2/5 m.s-1 on treadmill while kinematic (Raptor-4 motion analysis) and kinetic data (Force plate, Bertec) were captured at 150 Hz and 300 Hz, respectively. The internal joint moments in each plane were represented in the joint-coordinate system and were calculated using a standard inverse-dynamics approach and were normalized by the subject’s body mass as well as running cycle over 101 time points. Independent t tests were conducted to examine the symmetry of hip, knee and ankle moments between dominant and non-dominant joints during stance phase of running (P<0.05). Results: results of the present study showed no significant difference between two limb’s peak moments of lower joints in every three plane. Highest values of the dominant limb’s peak moments in sagittal, frontal and transvers plane were derived in (knee, ankle, hip), (hip, knee, ankle) and (knee, ankle, hip) respectively. Conclusion: Symmetry exists in lower joints three planar moments during running at the constant speed. According to the results dominant and non- dominant lower joints play propulsive and absorbent roles cooperatively

A Comparison of Kinematic Symmetry of Lower Limbs during Running at Different Speeds

Introduction: Symmetry and asymmetry of lower limbs are introduced as main critical challenges of human movement. The aim of this study was to compare the kinematic symmetry of lower limbs during running at different speeds. Material and Methods: The study was conducted as a quasi-experimental design. Twenty-eight professional runners (aged: 34.75±6.63 years) voluntarily participated in this study. Running at three progressive speeds (2.5, 3.5 and 4.5 m/s) was conducted by each subject on a treadmill while kinematic data were captured at 150 Hz. Peak angle of hip, knee and ankle joints during flexion were derived in the stance phase of running. Independent T-test were performed to examine the symmetry of peak flexion angles of hip, knee and ankle joints during running at different speeds using SPSS ver. 22 (P<0.05). Results: Findings showed no significant difference between two limbs in peak flexion angles of lower joints at every speed. Conclusions: Symmetry exists in peak flexion angles of lower joints in stance phase during running at the different progressive speeds. Coaches and biomechanists would achieve benefits of kinematic symmetry of lower joints in order to prevent injuries and optimize athletes’ running performance