Debating Biomechanics...

A few weeks back I received a comment in my blog that I didn't post because I was too busy working with my guys to debate it. Now that I have the time, let's address it. Below is the gripe:

"My name is Richard Mountney and I work as a qualified Biomechanist with a range of athletes from the European Union. I was directed to your blog by a colleague who is an avid golfer and has an association with a number of the European Tour players. There are many flaws in your blog reports with reference to your understanding of the body's physiological response to exercise, more specifically the 'Fitness tips' segments. Many of the claims you are making (e.g. flexibility creates power) are misleading and have no scientific foundation. If indeed you stand by your statements there needs to be a presentation of supporting research accompanied by the relevant application of exercises. I hope this will occur in future blogs. Best of luck."

While I appreciate Richard taking the time to write in, I obviously disagree with his thoughts on the matter. I ran his note by every PGA Tour strength & conditioning coach, biomechanics coach and golf fitness expert I work with in the mobile trailer and was hard pressed to find anyone who agreed with our friend 'across the pond'.

One colleague and friend of mine, Dr. Craig Davies, wanted to address this question specifically so I'll print his thoughts below as I think they'll bring some closure to this matter. It's a lengthy, technical explanation - but again, that's what our friend Richard Mountney asked for, so here goes: 

"The golf swing is a very unique and unnatural movement. It requires almost every muscle and joint in the body to move through large ranges of motion, with great coordination and freedom to be performed optimally. When we speak of power generation in the golf swing, we must consider many dynamics and fields of study that may not need considering in most normal activities.

Anyone who studies the golf swing gains an appreciation that no single field of study can fully measure, the intricacies of power generation and efficiency. To gain maximum efficiency in the golf swing there is a need to optimize physics, geometry, biomechanics, equipment technology, etc. An individual who can create optimal geometry in their attack angles throughout the golf swing will be able to create higher club head speeds than someone who has a great deal more muscle but does not have the mobility in their joints to allow for proper angles of attack. This is due to the ability of the first individual to utilize physics in creating advantageous motor arms and levers throughout the down swing.

Let’s try to think of this in lay terms by thinking of pushing a stalled car as an example. If all of your joints and muscles move through a full range of motion, you are able to swing your golf club with no restrictions and can attack the ball from whatever angle you like. Using this idea for pushing the stalled car, it would be similar to pushing a car that is in neutral and from the center of the back bumper. Because there are no motion restrictions, the car does not have any breaking mechanism in place and you are able to push the car wherever you want on the bumper to gain maximum leverage.

If a golfer has a restriction in their joint or muscle action, within their target side hip, it would be similar to the stalled car having the emergency brake on. The restricted motion would create a counter force force that you would have to push against in order to move the car. Also, if the range of motion within the target side hip is restricted, the golfer will be less able to attack the ball from the inside as easily as if the hip moved freely.

A restriction of this nature often results in the club head moving from an out-to-in path as it approaches the golf ball. If we think about this when trying to push the stalled car we are not only pushing a stalled car with its emergency brake on but we would also be trying to push the car on an angle from the back right bumper as opposed to the centre of the car.

Personally, I would rather push a car that was in neutral - without any brakes - and be able to push it straight rather than on an angle.

Let’s look a little more into the science of how power is generated and transferred in the golf swing.

If an athlete is performing a basic exercise in the gym (like the bench press), there are a limited number of muscles being utilized. The range and angle of motion required is finite and relatively easy to do define. As a general rule, the more muscle you develop in the chest, shoulder and arms, the greater the weight you will be able to bench press and the greater the speed you will be able to move a specific weight. This is because the function of these muscles during this exercise is relatively independent of the function of muscles and joints within other areas in the body (legs, spine, etc.).

Conversely, club head velocity at impact is dependent on an efficient transfer of energy through the body. The energy transfer moves through what is known as the body’s kinetic chain. The different parts of the body act as a system of chain links, whereby the energy or force generated by one part of the body (or link) can be transferred successively to the next link. The optimum coordination (timing) of these body segments and their movements will allow for the efficient transfer of energy and power up through the body, moving from one body segment to the next. Each movement in the sequence builds upon the previous segment’s motion and they all contribute to the generation of club head speed.

This kinetic chain is the linkage system that connects adjacent joints and muscles throughout the body. When one area of the body has a weakness or injury the transfer of energy is blocked, the body will then compensate for this blockage by overusing other distal body parts in an attempt to make up for this lost energy.

In an efficient golf swing, where the legs generate the majority of the power, large muscles contribute to force generation. When there is a “weakness” within the body’s kinetic chain, the energy produced by the legs is not able to be transferred up into the core and arms. As a result, the smaller muscles in these parts are placed under greater stress. In time, this will often lead to overuse injuries within the joints and soft tissues (muscles, tendons and ligaments) within these compensating body regions and a decrease in club head speed.

Note the word “weakness” referenced in the paragraph above. With respect to the transfer of energy through the body’s kinetic chain, weakness is not limited strictly to a limitation in muscular strength. Joint and muscle motion deficits and proprioception deficits are also considered to be a weakness. Having proper ranges of motion in each of the body’s segments is as important as each segment’s muscular strength.

In the earlier example, I indicated that when a muscle or joint is restricted in its range of motion, it acts like the emergency brake in the stalled car. The target side hip of a golfer goes through internal rotation during the down swing. When this motion is restricted, the pelvis is not able to continue rotating properly towards the target.

Instead, the joints in the lower back and other areas within the body attempt to compensate for this lost motion in the hips. The compensatory motion in these areas places a negative stress to the soft tissues and joints and will often lead to injury over time. It also leads to decrease in the efficiency of the power transfer up from the legs into the core and finally through the arms into the club. In essence, it acts like a brake.

I would like to clarify at this point that when a player has an excessive amount of flexibility well beyond the range of motion required to perform a golf swing, a decrease in power can be seen due to a lowering of cross fiber connections in the actin - myosin filaments - within the muscle and other neurological principles.

Excessive mobility is not nearly as common, in either amateur or professional golf populations, as restricted ranges of motion. However, athletes should be aware of this possibility as there are definitely cases where too much mobility decreases power generation within the golf swing. This can often be seen in young females who have too much mobility in their pelvis and do not have the muscular capabilities to stabilize the pelvis, leading to a decrease in the efficiency of the energy transfer through the body’s kinetic chain.

In essence, the excessive mobility acts like a leaky pipe in a car. The more hyper-mobile an athlete is, the larger the hole in the pipe. If you have a hole in the pipe there will be less gas making it from the tank to the engine than what you start with. This is what happens when a golfer is hyper mobile. They produce a lot power at individual muscles but this power is “leaked out” at each link through the body resulting in a decrease in over power output.

In closing, most athletes will be able to generate more power within their golf swing if they emphasize mobility within their workouts to allow for optimal geometry and physics to be utilized. On occasion, an athlete may demonstrate excessive motion within their muscles and joints and will not require an emphasis on increasing their flexibility."