How well do you know the biomechanics of initial contact in walking?

Study Notes

Initial contact is the beginning of the loading response and the first period of the stance phase.
It is also known as heelstrike, heel contact, footstrike, or foot contact.
The ground reaction force changes direction from upwards to upwards and backwards during the loading response.
The trunk is about half a stride length behind the leading foot at the time of initial contact, and it is twisted.
The amount of arm swing varies from person to person and increases with the speed of walking.
The mean elbow flexion is 8 degrees, and the shoulder flexion is 45 degrees at the time of initial contact.
The maximum hip flexion is generally around 30 degrees, reached around the middle of the swing phase.
The hamstrings are active during the latter part of the swing phase, and the gluteus maximus begins to contract around the time of initial contact.
These muscles start the extension of the hip, which will be complete around the time of opposite initial contact.
Fig. 2.11 shows the position of the legs and ground reaction force vector during the heelstrike transient.