Anatomy

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Muscles: Their Actions, Strengths & Weaknesses

There are three distinct types of muscles in the body;

• skeletal, being the muscles attached to bones and responsible for movement,
• smooth, surrounding arteries, the gut and other internal organs and is under the control of the autonomic nervous system.
• cardiac muscle which has the unique property of being able to self start and continue beating on its own. These cells are called "pacemaker" cells and continue to beat as long as you live.

Skeletal muscle is divided into various categories, according to their activity, or the contractile or metabolic/fatigue characteristics as well as their colour. One such classification is to define the muscle as either postural or phasic. Postural muscles (gastrocnemius, hamstrings psoas major) will resist fatigue and phasic muscles (quadriceps, gluteals, peroneals, tibialis anterior) are designed for short bursts of activity. As you are standing generally on both feet for your golf swing, and are nicely balanced, both phasic and postural muscles require training.

Skeletal muscles almost always act in combinations to produce movement. There are muscles whose role is primarily responsible for producing motion, other muscles play secondary or synergistic roles, that provide stability elsewhere in the body. A prerequisite for normal movement is that all relevant muscles act synchronously and appropriately. A prerequisite for normal movement is that all relevant muscles act synchronously and appropriately.

Get the terminology, and you'll sound like a personal trainer.

• A prime mover - is the main force that produces movement at a joint, this is also known as the agonist.
• A secondary mover - is a muscle that produces some of the movement or is recruited if the action becomes forceful. Synergists may be pairs of muscles which producing a motion while cancelling unwanted motions.
• Antagonists - are muscles having the action opposite to the desired motion.
• Stabilizers - prevent unwanted motion at joints other than those being acted upon by the prime mover.

Normal movement requires the agonist to shorten, antagonist to lengthen and stabilizers to act in concert, providing a stable base throughout the remainder of the body. It may be relevant to remember which activity you are exercising for so as to correctly exercise agonists, antagonists and stabilisers in their correct sequencing.

Eccentric Contraction

Given that muscle generally moves a joint when it contracts - otherwise the contraction is isometric - (muscle contracts but no movement occurs) terms such as eccentric and concentric are used to indicate the movement occurring. An eccentric contractions one in which the muscle contracts but the attached bones move in a manner which lengthens the muscle - think of the arm wrestle and an eccentric contraction is the loser - there is tension developed in the (biceps) muscle but the hand is being forced further away from the elbow.

Concentric Contraction

The muscle acting upon a joint contracts and the movement brings both ends of the muscle closer together.

Eccentric vs Concentric Contraction

The force produced per unit of muscle is larger during an eccentric contraction. It is therefore thought that the quickest way to increasing the strength of any muscle is to exercise it eccentrically. This may be the case, however eccentric contraction is known to produce post exercise soreness to a greater degree than other contractions, and the specific nature of how our muscles work mean that if you exercise eccentrically, then the concentric action of a muscle may not improve in strength - the solution is to mix and match and increase your eccentric exercise load slowly.

Muscle Overloading

To increase the functional strength in a muscle it must be used in a manner which the increase in strength is required i.e.. it should be overloaded. Depending upon the nature of the overloading the muscle will adapt to the increased needs - it will increase in size (hypertrophy) or increase in speed of response or the endurance capacity of the muscle. We are aware that strength training requires effort, the 6'th century Olympic athlete Milo of Crotona lifted a new born bull onto his shoulders each day, and as the bull grew so did Milo's strength. You should recheck your own weights to make sure that an adequate load is being used. The strength gains have been established to be approx. 2% per day. There are a number of other ways that a muscle can be overloaded.

The muscle can be subjected to:

• increased resistance
• increased number of repetitions
• increasing the speed of a movement
• increased frequency or duration of exercise regime
• change the nature of exercise (i.e.. from concentric to eccentric)
• change the angle (the range of movement) at which the muscle is being stressed.

It is my policy to begin with a few repetitions and increase this gradually - this conditioning reduces the post exercise soreness which leads to demotivation.

Muscle Power Work

Power is defined as "the rate of doing work" - roughly the same as explosive strength. To improve the power of a muscle do quick isotonics - both eccentric and concentric. Quick exercises that are functional also help - that means quick walking, stair climbing, jumps etc.

Muscle Conditioning

A muscles conditioning will depend upon the four components:

• Strength of the muscle
• Power of the muscle
• Endurance of the muscle
• Skilful adaptive ability of the muscle.

Various terms have been used to describe muscular contractions during exercise, these have become misunderstood and misused. Referring to the contraction of muscle these terms are popular:

Isometric Exercises

Isometric means "same length", so as the muscle contracts no movement is evident. Imagine two people having an arm wrestle and both are of the same strength - no one is winning and there is no movement of arms. Both would be "exercising isometrically". These exercises are often prescribed as the beginning form of exercise following injury - used when immobilised or when moving the region is painful. A muscle too weak to perform range of motion exercises will respond to isometric exercise.

As the isometric exercise prevents blood passing throughout the muscle each contraction should only be held for a limited period of time - say between 6 and 8 seconds, with an adequate rest between each contraction - say 15-20 seconds.

The isometric exercises should be done in groups of 10-20 repetitions, with the number of repetitions gradually increasing.

Isotonic Exercises

Isotonic means " same tension". This type of muscle contraction involves movement, against a fixed weight or resistance - often being a free weight (dumbbell or similar).

Isokinetic Exercise

Involves changing the force you are exercising against so that in stronger positions the force is greater, in weaker positions the force you are working against is reduced. The aim is to control the rate at which a muscle shortens. An almost totally unnatural method of exercise, requiring costly machines for very little additional gain off the tee. (get the idea I think this exercise is rubbish!)

Plyometric Loading

Involves loading a muscle suddenly and forcing it to stretch before the muscle contracts to elicit movement - e.g.. jump from a box to the ground, and then jump back onto the box. This type of exercise is good for explosive force improvement - it will give you additional gain off the tee.

Muscle Endurance

The measure of endurance of a muscle is its ability to perform repeated contractions or to sustain a contraction. The endurance of any muscle is a property of its fuel mechanism. It is worth looking at some characteristics of muscle energy supply.

There are two basic mechanisms - aerobic and anaerobic, meaning with and without oxygen. Aerobic mechanisms supply the slower twitch muscle - it means that the nutrient (glucose) is supplied with adequate oxygen for continued contractions. To train endurance it is the aerobic functioning which needs to be improved. For this type of work one should use low weight high repetitions, only very slowly increase the weights used.

Post Exercise Soreness

Why, after exercise do the muscles ache ? There may be more than one reason for this soreness, and it depends upon the type of exercise performed, it is well known that eccentric exercise will produce greater post exercise soreness than a concentric routine. It is a common myth that post exercise soreness is due to a build up of lactic acid. The body is quite capable of removing most lactic acid, most is absorbed within 20 minutes and at 2 hours the traces of lactic acid are extremely small. Some theories as to the reason why we get sore are: a) Fibre tearing:

• Fibre tearing - Fibre tearing implies that some of the muscle material is stretched and micro tears begin to appear. This theory is weakened by the fact that chemicals released following micro tears may be present without any pain.
• Build up of inflammatory materials - Histamines build up in exercised muscles, these irritate the pain sensitive nerve fibres.
• Connective tissue damage - Attached to muscle fibres, and adjoining bony structures is connective tissue - ligament, tendon, capsule. Eccentric contractions place more strain upon these and small tears on this tissue is thought to release pain stimulating chemicals. The difference between this theory and fibre tearing theory is the tissues involved are connective, rather than muscle.
• Inflammatory material release - Exercise induced blood pooling causes the release of substance P, a histamine. This irritates nerve fibres leading to pain.

The most credible is, I believe a combination of release of pain stimulating substances and connective tissue damage. This all means that correct, gentle exercise with adequate warm up and cool down phases will reduce, if not eliminate post exercise soreness.

Building the muscle size or muscle hypertrophy can be gained by exercises designed to overload the body. The response to overload of the muscular system is that the muscles become more efficient at coping with the load. This presents a number of difficulties for those who exercise in gymnasiums using machines which you exercise in a seated position - muscle specificity is the name of the response that gives a great increase in strength in the position in which you exercised but much less benefit in other positions.

If you exercise sitting and straightening your knees (exercising your quadriceps), the net gain is greatest when testing the quadriceps in a seated position, the gain is reduced greatly when testing the quadriceps in a standing position. The logic of this is simply that the body has over 400 skeletal muscles and the adaptive response to loading the muscular system initially is that muscle groups become more familiar at coping with the overload. The group activity depends upon the resting length of associated muscles, and sitting down places muscles in a different position that standing up. Note I am referring to strength gain not increasing the muscles size - muscular hypertrophy can be achieved by overloading the muscle. Many methods have been suggested for this - some suggest that you can sit down and connect yourself to electric muscle stimulators which will contract muscle under the electric stimulus - and increase in size - most research tends to dismiss this theory.