BIOMECHANICAL STUDY OF LANDING CHARACTERISTICS DURING SPRINT AND ITS RELATION TO RUNNING INJURIES

Abstract

There have been very few studies involving running techniques and the injuries related to them. At best, these relationships are only empirical. Since, the loading or rate of movement of the musculoskeletal structure has been referred synonymously with injury, there is a need to investigate the cause-effect of running techniques and the loading characteristics associated with them to take a further step in understanding the cause of injury. Three studies were done to i) quantify the landing characteristics of various sprinting technique's, ii) investigate the loading of the lower limb's musculoskeletal structure in relation to different techniques of sprinting and iii) investigate the muscle loading characteristics at the lower limb's joints and sprinting techniques during landing. In study 1, four subjects, aged 13 to 15 weighing between 45 to 65kg, performed a one step approach onto an AMTI forceplate using 3 different landing methods, normally instructed verbally by coaches i) Hard landing, ii) Soft landing and iii) Own method. The experiment showed that soft landings can be quantified as having a smaller Vertical ground impulse/Horizontal ground impulse (V /H) ratio and hard landings have higher V /H values. Own method showed no inclination to the former two methods. In study 2, the same four subjects had to run onto an AMTI forceplate using four styles normally instructed verbally by coaches : i) Own, ii)Long, iii)Fast and iv) Soft methods. Their runs were captured using the Peak motion analyser equipment in the laboratory. Subsequently, they ran outdoors over 10m. The experiment showed that there was a strong relationship between good sprint times and smaller V /H ratios (r2 = 0. 85). A good relationship was found for the data for angular impulses and peak moments about the joints in the three orthogonal directions. The ankle's angular impulse about the anterior-posterior-axis and peak moments about the lateral-medial-axis had values r2=0.46 and r2=0.3 respectively. Generally, positive relationships were established. In study 59.7kg) 3, 10 subjects (average performed the same runs age of 14. 8 as in study and weight of 2. The muscle loading for various landing styles were investigated. Only the gastrocnemius had a relatively good correlation with the V/H ratio (r2 =0.53). As for the rest of the muscle groups no consistent results was found. However, a lower V/H will most likely lead to faster 10m run times (r2=0.63). In conclusion, these studies found that characteristics of various sprinting quantified where soft landings have low landings have higher ones, ii)soft landing i)different landing techniques can V /H values and (low V/H value) be hard was related to lower potential for injuries and faster run times and iii) only the gastrocnemius had low potential for injury during soft landing.