BOX 4.1 RUNNING MECHANICS DURING THE MAXIMUM SPEED PHASE
Leg Action
Sprinting involves a sequence of strides. During the stride at maximum speed, the leg cycles through three
main phases: i) the drive phase; ii) the recovery phase; and iii) the support phase.
In the drive or take-off phase, the drive or rear leg extends at the hips, knees and ankles and forcefully
propels the body forward by pushing downwards and backwards into the ground at the ball of the foot. At
the same time, the knee of the other (front) leg is driven upwards and forwards until the thigh is parallel to
the ground.
The recovery or flight phase starts as soon as the driving foot leaves the ground. The knee of front leg
reaches it maximum height after which the lower leg swings forward and then extends at the knee until
the foot strikes the ground. The rear leg is cycled through by a closing of the knee joint followed by
flexing of the hip.
The support phase occurs after foot strike of the front leg. During this phase, the weight of the body is
supported by the entire foot and the body’s centre of gravity passes over this foot until the drive phase is
initiated.
Arm Action
The arms and legs work in an opposing manner. For example, as the knee of the front leg comes forward
during the drive phase, the arm on the same side is forcefully driven backwards. The arm swing should
occur from the shoulder and the upper and lower arm should make a 90 degree angle at the elbow. The
hands should not reach across the chest during the arm swing, which ranges from the side of the face to
the hip.
Posture
The torso should be erect throughout the entire stride
Common Errors
For coaches that have little experience with sprinting form and technique, the main errors to watch out for
are:
- Bouncing (too much vertical height achieved with each stride)
- Insufficient or incorrect arm action
- Short stride lengths (poor leg strength, power or flexibility)