Introduction to Sports Biomechanics: Analysing Human Movement ...

Foot descent – starts as the forward movement of the leg and foot stops, ends at first
foot contact. The hip and knee extend (see also Figure 3.13(a), region g–a) after the
arresting of the forward leg swing by the hamstring muscles; the gastrocnemius
muscle at the back of the calf is pre-activated for landing. This phase’s main
function is to have the foot strike the ground in an active landing, to prevent
braking of forward movement of the centre of mass.
Phase analysis of more complex movements
Three examples are given below, focusing on the name and main functions of each
phase only.
Phase analysis of volleyball spike
This is probably best analysed in seven phases:
1 Run-in: generating controllable speed.
2 Landing: impact absorption.
3 Impulse drive: horizontal to vertical momentum transfer.
4 Airborne phase of preparation: as ballistic.
5 Hitting phase: as ballistic.
6 Airborne phase to landing – airborne recovery: as ballistic.
7 Landing: to absorb impact, control deceleration and prepare for next move.
Phases 4 to 6 are seen to follow the ballistic sequence within a more complex
movement.
Phase analysis of javelin throw
1 Run-up: generating controllable speed.
2 Crossover steps: ‘withdrawal’ of javelin to extend acceleration path; transfer from
forwards to sideways action.
3 Delivery stride – the action phase; similar, in many ways, to that for ballistic
movements.
4 Recovery – to avoid crossing foul line.
Historically, phase 2 would have been split into the withdrawal and one crossover step.
Phases 2 to 4 follow the ballistic sequence within a more complex movement structure.
Phase analysis of front crawl swimming
QUALITATIVE ANALYSIS OF SPORTS MOVEMENTS
Swimming can, conveniently, be broken down into the time spent starting, stroking
and turning. Focusing only on the stroking part of this subdivision for the front crawl,
we can identify the following phases for each stroke:
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