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POSTURE AND MUSCLE BALANCE

Posture has become quite a buzz word in recent years. However, the understanding, importance and methods of correcting posture are often misunderstood.

There are many definitions of posture. Two include:

“Posture is the position from which all movement begins and ends.” (P. Chek, CHEK Golf Biomechanic Certification Manual)

“The position from which the musculoskeletal system functions most efficiently.”

(M. Feldenkrais, Body and Mature Behavior)

In addition to the definitions above, there are two main categories of posture: static and dynamic.

Static posture

Static posture may be defined as “…the position of the body at rest, sitting, standing or lying” (P. Chek, CHEK Golf Biomechanic Certification Manual). This means that if you have poor posture before you move, you are more likely to have poor posture whilst moving. Therefore, poor static posture could well be expressed in your movements.

Dynamic posture

Dynamic posture may be defined as “the ability to maintain an optimal instantaneous axis of rotation in any combination of movement planes at any time in space” (P. Chek, CHEK Golf Biomechanic Certification Manual). As a simple analogy, you can think of your spine as an axis of rotation (like a crankshaft) and your arms as a means by which motion at the axis is expressed (like the connecting rod). If your spinal axis is faulty and expresses the exaggerated curvatures that go hand in hand with poor posture, your capacity to rotate efficiently will be significantly reduced. If your spinal axis is well aligned, you are far more efficient and are likely to move and perform to your full potential.

Optimal posture is maintained when muscles surrounding a joint or joints are in balance. Good ‘muscle balance’ simply means that the muscles are at their optimal or normal length and tension. A muscle imbalance is when a muscle on one side of a joint is tight and its opposing muscle (antagonist) is long and potentially weak. This causes the joint to lose its optimal axis of rotation and can lead to excessive wear and tear on the joint and increase the likelihood of injury during sport.

It is beyond the scope of this book to instruct you how to maintain optimal posture and muscle balance. Instead, we would suggest that you receive advice from a qualified professional – or read Anatomy of Yoga for Posture and Health by Leigh Brandon and Nicky Jenkins (see page 144). It is also advised to achieve the best possible muscle balance before beginning the exercises in this book.

Posture and alignment

The gravitational pull that is exerted on the body acts through the body in a straight line towards the earth’s centre. In a standing position, neutral alignment occurs when landmarks such as the ankles, knees, hips, shoulders and ears are in line with the pull of gravity. The body also requires balance from front to back and side to side, allowing it to maintain its position against gravity with minimal effort. The more the body is out of alignment, the more energy it uses to resist the gravitational pull. For most athletes, poor posture could not only cause injury, but also waste vital energy and could make the difference between winning and losing.

In neutral alignment, the pelvis is in a neutral position with the pubic ramus and the anterior superior iliac crest vertically aligned. In this position, if the pelvis were a bucket of water, no water would spill out. With an anterior pelvic tilt, the water would pour out the front, while a posterior pelvic tilt would cause the water to pour out the back.

As we exercise and move the body in different positions, such as squats or lunges, gravity continues to affect the body, the critical points of balance shift and we are required to work harder to maintain balance and alignment. When lifting heavy weights, despite the fact that your balance is shifting, in some instances it is still important to maintain a neutral spine. ‘Neutral spine’ in the instance of performing squats would require the maintenance of a straight line through the ear, shoulder, pelvis and hips, but not necessarily in a vertical line.

Poor postural control and alignment affect both your quality of movement and the safety and effectiveness of any exercise, as postural compensation is likely to occur. This means that the joints used, joint actions, range of movement and involvement of the various stabilizing and mobilizing muscles will change from the ideal. For instance, in the squat, if you had a tight soleus (calf muscle) in the right leg, your body weight would shift to the right as you descended in the squat. This would place more stress through the medial left knee and lateral right knee.

Posture and alignment

One common classification of muscles is whether they are performing a stabilizing or mobilizing function.

A mobilizer muscle (also called a phasic muscle) is a muscle primarily responsible for creating movement across joints. For example, the gluteus maximus extending the hip joint during the lunge (see page 59).

Stabilizers (also known as tonic muscles) are muscles whose prime purpose in the body or in a given movement is to maintain the stability and alignment of the rest of the body, so that effective movement can be performed by the mobilizing muscles. For example, in the chin-up (see page 83), the rotator cuff muscles of the shoulder stabilize the shoulder joint as the latissimus dorsi and pectoralis major adduct the shoulder joint to pull the body up to the bar. Certain muscles, by virtue of their position, shape, angle and muscle fibre type, are more suited to work as stabilizers than mobilizers. Stabilizing muscles tend to be deep in the joint, have lots of endurance, but can’t produce much power. Mobilizer muscles tend to be more superficial, have little endurance, but can produce a lot of power.

An important yet controversial area of the body is the abdominal musculature, which is widely believed to help stabilize the body, particularly the lumbar spine, rib cage and pelvis (which are the foundations for the arms and legs), but how it achieves this stability is not universally accepted (see pages 48–52).

Classifications of speed

In sport, different events require different speed qualities. For instance, a 100 metre sprinter will require starting speed, acceleration, reactive speed and maximal speed. However, a tennis player would require starting speed, acceleration, deceleration, agility, reactive speed and lateral speed.

You will need to analyze your own sport and decide which speed qualities are vital. In team sports, you may also need to be more specific. For instance, the speed requirements may be different depending on which position you play or even your particular style of play.

For instance, a wide receiver in American football would need maximal speed where perhaps a lineman would not. A rugby winger would require maximal speed, but a volley ball player would not.

In many sports, particularly team games and ball sports, the speed of thought or anticipation is essential. Failure to anticipate your opponents’ or team mates’ movements or the movement of the ball can be the difference between success and failure. Whilst it is beyond the scope of this book, speed drills should be performed in competition-specific conditions once you have perfected your skill. This will allow you to develop speed of thought in competitive situations.