The biomechanical specificity of running drills to sprint performance

Drills are considered important in the coaching of correct sprinting technique as they establish the optimal movement and coordination patterns of sprinting. However, there limited of research on the kinematics and muscle activation of drills compared with sprinting. Therefore, the aims of this thesis were to advance the understanding of the movement and muscle activation patterns of drills and their specificity to the movement and muscle activations of sprinting. This research examined the optimisation of event specific technical training (i.e. drills) for sprinting based on kinematics and muscle activation patterns. This thesis consists of a series of linked studies examining coach and athlete practices and empirical studies comparing kinematics coordination and muscle actions between drills and sprinting. Coaches (n = 209) were found to base sprint drill selections on what other coaches were doing rather than having a scientific rationale for selecting drills. The two most popular drills selected by coaches were the A-skip and heel flicks. These two drills formed the basis for further investigation of the A-skip and heel flicks throughout this thesis. To provide further insight on drills and sprinting, a kinematics study was conducted to determine the movement and coordination patterns of drills and compare these with movement the coordination patterns of sprinting. The results of this study found similarities of knee movement in heel flicks (RMSD 8°) between the knee angles, but difference in hip action. Similarities of hip action in A-skip were found but there were significant differences in knee action (RMSD 36°). Observations from the kinematics study were that further research was needed examining the muscle activations of the lower limb during sprinting, A-skip and heel flicks. In examining the muscle activations of lower limb muscles during sprinting, there were various similarities and differences when comparing the drills to sprinting. Additionally, it was shown that there was large variability between participants (n = 16), this was apparent when examining the effect sizes which indicated some similarities and some large difference between drills. Small differences and large differences were found between sprinting and heel flicks in the right biceps femoris with a small effect size (0.304) and right rectus femoris with a large effect size (0.964). It should be noted that there were limitations to using surface EMG analysis to detect muscle activations; this is due the fact that different muscles can be used in many different ways to initiate the same action (muscle redundancy). The final study examined the optimal movement and muscle actions patterns using musculoskeletal computer simulation modelling model. The current model was validated based on comparisons between experimental muscle activity and model predictions of muscle activity. Near perfect correlations for kinematic data were noted between both experimental and computer simulation model data, 0.993 for the 5th metatarsal and 0.999 for the greater trochanter for the A-skip drill. This thesis has provided information on coaches and athletes understanding of drills and their enhancement of technique. The experimental work has provided some valuable information on the movement and muscle activations of A-skip and heel flicks compared with sprinting. There are some similarities and differences observed when comparing A-skip and heel flicks drills to sprinting. Therefore, implementing both drills into a programme may be useful as they do replicate important movement and activation components of sprinting.