BIOMECHANICAL ANALYSIS

ticularly important in the bend pattern (5); inactivation of the inner unit in the bend pattern can also lead to injury of the sacroiliac joint, with concurrent back and hip pain.

Push Most functional pushes in daily activities are per- formed standing and often with on e arm

or on one leg. The Figure 5a: and inset 6b:

environment in developed countries. People spend all day sitting

while they

eat, travel to and from work, at work, and then at home watching TV and have lost their ability to perform a full squat. Many people coming into a gym are afraid to 'squat' as an exercise, but ask them to sit down and stand up again and most can do this with relative ease due to the security afforded by the chair or bench beneath them. However, the inability to balance your own centre of gravity over your own base of support in a squat pattern will cause you to fall over, often backwards, when trying to squat. This is a particular problem in the elderly, where hip fractures secondary to falls are a major cause of injury and death. Medial rotational insta- bility (over-pronation) also leads to dys- functional squat patterns as the knees buckle inwards causing excessive sheer and torsion on the knee joints.

Lunge Climbing stairs and stepping over an object, or stretching to get the vacuum under a table are everyday examples of the lunge or variations thereof (Figure 6). All commonly accepted muscle chains or systems, such as the deep longi- tudinal, anterior, posterior and lateral are important in the lunge (3) and weakness or dys- function in either will lead to instability in the spine, pelvis or hip, pronation patterns and potential injuries to the ankle, knee, hip and sacroiliac joints. Balance issues and medial rotational instability are also common issues in the lunge pattern, as in the squat, among

24 Figure 6a and inset 6b

those with incomplete infant motor devel- opment.

Bend From a mother picking up after a child to delivery person picking up a package to a mechanic bending over the bonnet of a car, the bend pattern is ubiquitous in everyday life. Light items can be picked up with a round-back lifting posture, which is important to use regularly to maintain strength in the spinal ligamen- tous system (4). Heavier objects

those

that you cannot pick up at least 20 times in a row or that naturally result in breath- holding for reasons of improved stability should be lifted with a lordotic lifting posture, where the lumbar curve is main- tained to reduce the risk of spinal disk injury. Bending, particularly when coupled with twisting, is a well recognised cause of disc herniation, brought about by over- load or repeated and excessive wear over a period of time due to dysfunctional mus- culoskeletal support systems and poor movement patterns. The inner unit is par-

Figure 8a and inset 8b

amount of weight that someone can push from a lying position, e.g. a bench press, generally bears no correlation to the amount they can push while unsupported using one arm when standing, eg. a single arm cable push. This is because a func- tional core - which should naturally result from our infant developmental stages - is crucial for a functional push, as this pro- vides a firm foundation for the arm and shoulder musculature to work from, and also anchors the pelvis and lower extremi- ties. Dysfunction in the core often leads to overwork in the shoulder joint

as is so

common in professional pitchers and bowlers who may undergo repeated surgery for rotator cuff injuries and similar.

Figure 7a and inset 7b

Pull As with the push, most functional pulling is done standing, often predominantly on one leg while generating force with the opposite arm. In the pull, the arm and scapula should work synergistically, beginning and ending movement togeth- er. A common error by exercise instructors is to retract the scapula adductors first, then pull with the arms. This sets up faulty timing in the musculoskeletal sys-

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