Introduction to Sports Biomechanics: Analysing Human Movement ...

Extension and flexion (Figure 6.2(b)) refer to frontal plane movements away from
and towards the index finger; hyperflexion (Figure 6.2(c)) is the movement beyond
the starting position.
Opposition is the movement of the thumb to touch the tip of any of the four fingers
of the same hand. It involves abduction and hyperflexion of the thumb.
Circumduction of the arm and leg
The movement of the arm or leg to describe a cone is called circumduction and is a
combination of flexion and extension with abduction and adduction. Several attempts
have been made to define movements in other diagonal planes but none has been
adopted universally.
Movements of the shoulder girdle
The movements of the shoulder girdle are shown in Figure 6.3, along with the humerus
movements with which they are usually associated.
Elevation (shown in Figure 6.3(a)), and depression are upward and downward
linear movements of the scapula. They are generally accompanied by some upward
(Figure 6.3(b)) and downward scapular rotation, respectively, movements approximately
in the frontal plane. These rotations are defined by the turning of the distal
end of the scapula – that further from the middle of the body – with respect to the
proximal end – that nearer the middle of the body.
Protraction and retraction describe the movements of the scapula away from
(Figure 6.3(c)) and towards the vertebral column. These are not simply movements
in the frontal plane but also have anterior and posterior components owing to the
curvature of the thorax.
Posterior and anterior tilt are the upwards and downwards movement, respectively,
of the inferior angle – the lower tip – of the scapula away from (Figure 6.3(d)) or
towards the thorax.
Pelvic girdle movements
THE ANATOMY OF HUMAN MOVEMENT
Changes in the position of the pelvis are brought about by the motions at the lumbosacral
joint, between the lowest lumbar vertebra and the sacrum, and the hip joints.
Movements at these joints, shown in Figure 6.4, permit the pelvis to tilt forwards,
backwards and sideways (laterally) and to rotate horizontally.
Forward tilt, from the position in Figure 6.4(a) to that in Figure 6.4(b), involves
increased inclination in the sagittal plane about the frontal axis. This results from
lumbosacral hyperextension and, in the standing position, hip flexion. The lower
229