Biomechanical Aspects of Physical Therapy

[Jason Silvernail]

Anoop had asked in a previous thread:

Anyway, back to the question, I am just curious to know if there is some benefit to muscle balance or improving movement patterns or focusing on the biomechanical model when it comes to training athletes. What do you think or have you had some experience?

We talk a lot on this board about neuroscience, pain and movement physiology, and the inadequacy of the biomechanical model to explain pain and provide rational solutions to chronically painful problems.

When it comes to performance training, this is a totally different world. I have had a lot of experience with injured athletes and Soldiers, and I have found my biomechanics knowledge very useful - but my knowledge of motor control is just as important.
There is some data out there to support the presence of muscular imbalance at the shoulder as an independent risk factor for pain, and there may be something to this for other joints as well. So designing well-rounded programs for athletic performance is important.

Where much of the PT world goes wrong, is applying this same biomechanistic thinking about performance and using it to try to address and understand the origin of mechanical pain in the absence of trauma, which often has little to do with mesodermal/connective tissue structures. As they say, all pain is neurogenic. It has dismayed me to see many personal trainers attempt to move in the direction of rehabilitation, taking their exercise knowledge and a cue from physical therapy, and attempting to diagnose and treat all sorts of issues they do not have the education to approach, much less attempt to treat. The National Academy of Sports Medicine in particular is guilty of this in their educational system, in my opinion.

I think for your average outpatient physical therapist, it's important to understand biomechanics and some performance training, as you see many connective tissue injuries which require remodeling and reconditioning. I would guess this is a much smaller percentage of the total caseload overall, however, depending on the practice situation.

Athletic and sports training is better left to personal trainers and strength coaches unless the PT has a definite interest and possibly a certification in this area. PTs who design performance training programs tend to produce programs that look like rehabilitation - partial range of motion exercises, loads too low, avoidance of high velocity movements often key in sports training, inadequate progression, avoidance of squatting and bending, etc.

PTs who are interested in this area or in improving their knowledge base (or in just being amazed about how little you know and the depth of knowledge a good strength coach has) are encouraged to look into the National Strength and Conditioning Association and their Certifications.

[Barrett Dorko]

Jason,

I think this should be sent to all the academics we have. It's perfectly defendable and, if adopted, would transform the PT curriculum.

Of course, it's that last part that is so hard.

Does anybody here have any influence with the colleges?

[Jason Silvernail]

I certainly don't have much influence. Here in Germany, I don't even have PT students in the clinic....

[anoopbal]

Hi Jason

Thanks for the the new thread.

To think of it, I think the the psychological factors are equally important ( or sometimes more important) than the biomedical issues for athletes. For example, the same type of injury occuring at the Achilles tendon of a football player and office worker; the office worker simply ignores it as nothing more than an iritating discomfort; however, the athlete with the same injury interpret this as a major threat to their career, fitness, livelihood and their whole life and these negative thoughts and fear can lead to chonic pain (from an article from Luois Gifford).

I have had similiar problems. I used to feel and think about the pain my low back whenever I bend to brush my teeth, do cardio and so on for years. And for me this was important bcos this meant I could never do the big lifts like deadlifts and squats. But ever since I read Explain Pain and about pain physiology, I have never felt the pain again. Now I am starting to do partial deadlift and planning to gradualy come back to full deadlift. Now I understand hurt means not harm. I amjust mazed how much the change in belifs or undersatnding pain can do to you

Another aspect is anytime you pin it down to a biomechanical problem like muscle balnace or try to explain on the basis of structural problems, you are invariably creating fear of movement or weakness which seems to have the opposite effect. For example, I know one of the leading rehab expert in sports who avoids any sort of rotational and flexion movement in his athletes bcos he think it is extremely dangerous and is the the major cause of low back problems. And where did he get this infor from? Shirley Sahrmann. And as you said, if there is a biomechanical aspect involved in the pain, I think its really important to convey it your athletes without conveying the negative connotations associated with it.

I have more to ask. Iwill write soon

anoop

[nari]

Anoop

I have seen pain education resolve pain without any other intervention of any kind. It seems to depend on the person's receptiveness to information, how strongly their memes are tied to old beliefs and what they think of their pain - does it simply become an expression of themselves?.....

We probably do not appreciate often how we facilitate pain by telling patients NOT to do this or that action and thus creating fear. We do not even cue to the fact that we may not be aware of any conscious fear. A person can experience sudden LBP after a strenuous and repetitive activity of flexion and rotation; if, after a bit of a rest, that activity is resumed, less vigorously perhaps, the pain often resolves. It is more than coincidence.

Nari

[BB]

Hi Anoop,

I once set up a performance enhancement program for athletes based on biomechanical assessment. I eventually realized that even if a person takes their body through space in the "right" or "balanced" way, that says nothing of efficiency.

Someone may have great balance of the muscles about the shoulder, but that balance may be like 2 elephants sitting on a teeter totter. They are heavily resisting each other, but in a balanced way.

Efficiency of movement I feel is more important to performance than quality of body mechanics.

[ian s]

Cory,

I remember working with a national level boxer who was given all these muscle imbalance fixation/setting exercises by lots of people ......
Often imbalances are co contraction issues not biomechanical problems,sometimes they relate to personality variables , psych social stresses and mirrored learnt patterns of behaviour .
http://www.npr.org/templates/story/s...toryId=6070170
You might like a listen to this ..i have read and practised some of Danny Dreyers ideas --makes sense .
Jason , yes mechanics are useful . A well rounded apprentership inc trauma/orthopaedics , rehab makes this obvious . Applying this to insidious pain states and ubiquitious psych soical stresses is often counter productive but this is where eduction fails and alternative health often intervenes ?
ian

[Jon Newman]

I think Jason's summary is pretty good. While hurt does not equal harm, harm still exists and understanding what might lead to it is a good idea and knowledge of biomechanics can certainly help. Also, under better conditions (nervous system not sensitized) the gap between hurt and harm is pretty small so hurt can be considered a pretty good guide.

Biomechanics may also tell us what is efficient but it doesn't do too much work as it pertains to how a person will feel about it. Consider for example Paula Radcliffe

[anoopbal]

My guess is that improving you stability and mobility is great for injury prevention. Like, how a tight or immobile ankle can cause stress to be transferred up to the knee joint (but does it cause pain??). Similar to concept of how one joint compensates for the othe joint. Gray Cook has a lot to say about this. But he talks more abt performance and efficinecy and less abt pain and injuries in his book. I think he is being cautious.

But once the injury has happened and turned into a chronic one, I am assuming the nervous sytem had a lot to do with this conversion. So even if the biomechanical problem is solved, the nervous sytem is still over reacting. Maybe you have to focus on both.

But, at the same time, sometimes the biomechaical moel is clueless when you see people like Paula in Jon's Post. I have read how Ben Johnson's right knee shifted to the right right every time he ran. Annd he never had any injuries whci is rare for sprinters. The coach never bothered to fix it, but I am prretty sure that today's strength coaches might go crazy over getting it fixed.

Anoop

[Jon Newman]

Update: Paula Radcliffe wins NYC marathon

[EricM]

Now just over an hour into the women's marathon in Beijing, I'm learning that Paula Radcliffe suffered a stress fracture which limited her ability to train during the last 1/2 year. While she wasn't running, she was training, and apparently doing some "space age training" according to some headlines. I'm interested in what she might have been doing. Does anyone know? It's hard to find any details.

[Jon Newman]

Pretty spectacular solo win.

Too bad for Paula. The announcers noted that despite her injury and her short "walking it off" stint during this run that she was going to finish because of criticism for failing to finish in her last Olympics. What a tragedy if that's true.

[dsteven12]

Originally Posted by BB

Hi Anoop,

I once set up a performance enhancement program for athletes based on biomechanical assessment. I eventually realized that even if a person takes their body through space in the "right" or "balanced" way, that says nothing of efficiency.

Someone may have great balance of the muscles about the shoulder, but that balance may be like 2 elephants sitting on a teeter totter. They are heavily resisting each other, but in a balanced way.

Efficiency of movement I feel is more important to performance than quality of body mechanics.

I agree also that efficiency of movement has more to do with balance, but it also depends on what sport the athletes play that determines the movement efficiency. I do have a strong belief in core movements that all athletes share - athletic ready stances, hip turns (instead of pivot steps), and more that are not commonly trained positions that I believe should be with proper progressions added. Although the positions themselves should be trained as skills, but the broken down pieces can be loaded depending on the goal.

Looking at great athletes who haven't been injured within 5-10 years and noticing their mechanics there are huge differences in the amounts of availability mobility in neutral and sport positions alike and using much more minor nuisances that aren't normally observable unless trained or naturally used to seeing it - great football/basketball players tend never to track their toes during a run as their knees have to hit the proper force vectors, while they are dashing down a court trying to evade the defenders. Of course if we are talking strictly of sprinting then knee tracking is much more linear, whereas in most sporting endeavors in the first few feet or yards depending on the sport and defender position the knees are constantly shifting medially/laterally (often untrained positions in sports besides side lunges, side steps, etc.) and even then the knee follows the line of foot, whereas in sports it does not. From a neural standpoint, we have to create fear reduction in the Central Nervous System so it avoid inhibiting strength potential/skill potential and in terms of tissue we want strong ligaments/tendons/muscles to support and aid in lateral motions.

Thoughts?

[smith]

Yes, Steven, if you could develop your idea of training hip turns instead of pivoting.

I think it is defense over defect. Athletes move a certain way to defend their body, or protect against nerve irritation. That is why dynamic warm-ups improve sport performance and decrease injurys. Activate and turn on nerves/muscles, to better protect the nervous tissues.

[dsteven12]

Hip turns are essentially a minor hop w/ both legs (less than a bunny hop, feet just get high enough to clear ground, while avoiding friction of ground), whereas a pivot step is when you turn specifically on the ball of the foot on one ground.

Both are meant to rapidly reorient yourself/switch directions, but pivot steps are normally much slower (one leg moving, vs both legs moving, better overall body control because of alignment).

I do agree much with the idea of threat/stress/nerve protection as much of the bodies rolls seem to really help the brain out, but I'm not sure as to what that statement was in reference to? Specifically the knee tracking to evade defenders?

[smith]

Yes Steven, I'm also confused? Tracking of toes when they run? Maybe in the future we can speak this way, internal rotation of femur in the transverse plane. I rarely see athletes hop on the playing field, lots of pivots though. Lower the center of gravity, the quicker the change of direction. Hence the pivots. Unless you've seen research otherwise?

[dsteven12]

Toe tracking is a term used in S&C - simply a laymen's term to describe knee osteokinematics. I'm not speaking of hopping in the literal sense, and pivots (which I'm assuming you mean a foot plant and direction change?) are essential when evading an opponent's flurry, I'm speaking more in a transitional sense - 90 degree to 180 degree turns - this is more along the lines of Football and Basketball - opponent's side or on a fask break for the offensive team. Another way to think of a hip turn is simply both legs moving to make a transition, rather than from one foot pivoting.

Pivots in terms of major turns tend to have increased friction/drag, whereas minor hops to transition tend to take less timing, since you don't have legs acting as breaks. On the other hand, when performing cuts, which is what I'm assuming you meant by pivots, it's a different story - although I'll refrain comments until I understand what you mean.

[smith]

I've been in strength coaching over 20y, and never heard the term toe tracking Steven. Maybe if you could point me to research somewhere?

Most of my knowlege of pivots etc. come from the ACl research; Hewitt's Cincinnatti group and a guy by the name of Taft. Essentially, keep the pivot knee over the second toe, don't allow the femur to buckle in the frontal plane; for the cincinnatti group. Taft would have you also do a plyometric push-off on the pivot leg with what may be a hip turn. Taft also breaks down pivots/cuts into speed cuts and change of direction cuts. His ideas came from studying Barry Sanders. One foot on the groud though. I'd think you would like Taft's ideas. He often gives talks etc.

[Jon Newman]

Forget about the f--cking toe.

[TexasOrtho]

Jon this doesn't happen alot so I figured I'd bring it up here...I completely agree. Tuck the foe and don't micromanage the movement.