9-20-15-ferez

New Science May Shed Light on Movement of Pros
by Ferez S. Nallaseth, PhD

September 19, 2015 - New science may explain new reasons why squash pros move so explosively and for so long without tiring - subconscious adjustments of movements to conserve energy!

We have all watched squash pros make moves on the court – there is a huge range! And these moves are made for long periods! They include such things as stepping from the Service Box to the T or driving from the T to the front corners to recover a drop! And then making or recovering drops that are millimeters above the tin and the floor and often stuck to the sidewall and recovered with the lightest of touch. This range of basal to peak velocities along with the ‘deep digs’ is known as explosivity and arrhythmicity to Sports Physiologists. They are measurably better developed in Pros than in Juniors (1 - 5). An obvious reason for Pros lasting through this and much more in the long games that they grind out is strength and conditioning. But they are not the only reasons – and Coaches and Players have long thought of this as an unmeasured observation!

Some new work emerging from Dr. J. Max Donelan’s group sheds light on this ‘additional factor’ (6, 7). Basically Scientists used a Robotic Exo Skeleton to change the stride lengths of walkers (experimental subjects) and measured the energy consumed with a facemask to record mouth/nasal gas exhalation. Stride lengths were altered from one of their choice, with the associated low energy consumption, to a length associated with higher energy consumption. These subjects quickly shifted back to their stride length of choice with its lower energy consumption (7). Although deeply ingrained Evolutionary, Developmental, Genetic and Neuroscientific traits are invoked as explanations, the latest paper from measurements in Robotics and Motion Mechanics implies some involuntary and immediate control determined by Energetic costs. Energetic costs were also interpreted to play a likely role as an active modulator than a passive by-product of, stride length (6, 7).

The interpretations in the above work identify the brain as the primary organ controlling these movements. However, the spinal cord has also been shown to coordinate complicated movements such as walking or swimming and independently of the brain (8, 9). Using powerful new technologies in microscopy and genetically engineered mice researchers have identified the specific (motor) neurons, networks and reasons for this control. They have shown that “motor neurons in different parts of the spinal cord control different limb muscles, and different types of neurons control the frequency, precision, and left-right alternation pattern of walking.” And so all of these Spinal Cord networks and the muscles that they control could also become more efficient as Squash Players mature on the court (8, 9).

On the Squash Court, there are other dimensions which some players know and do far better than others! They adjust postures, strides and steps in different phases of the run up to the ball. They are far more fluid, know when and how to approach the ball without running into it! They arrive early and yet leave enough time and space to be able to swing at the ball to make a good clean stroke! This is clearly seen in the progression of Squash Players transitioning from levels of, Beginners to Juniors to Amateur Champions to Pros – and clusters of levels among the Pros!

These perceptions were reinforced by measurements that emerged from 2 research groups which applied computerized versions of Jonah Barrington’s ‘Ghosting’ (or Star Drills) to capture the arrhythmicity and explosivity of basal to peak movements of Squash Players (1 - 5). These were the Squash Specific Test (ST) compared with a standard Tread Mill Test (TT) with well-established physiological parameters reporting the intensity of both tests (1 – 5). By excluding the ball and so interruptions during the times it goes out of play ‘Ghosting’ allows the exertion of a sustained cardio-respiratory pressure. However, because when the ball is in play, it is itself a principal motivator in any match this takes out a major cardio-respiratory pressure. For example sprinting to make ‘deep gets’ that are millimeters off the court this has to constitute an immeasurably large contributor to cardio – respiratory pressure. So computerized ‘Ghosting’ and ST tests are at best some small reflection of a realistic measurement of on court cardio-respiratory pressures and energetics!

In the first study, players who were Juniors were assigned rank performances by both ST and TT tests. There was a significantly greater difference in the correlations (>1.7x with p range >50x) between the Squash Specific Test (ST = 0.90, p<0.001) than the TT test (TT= 0.52, p>0.05) in their respective correlations with the ranks established by various physical, physiological and biochemical reporters (1). Of most importance the ST test predicted the performance of the players in routine competitive play (tournaments) far better than the TT (1). This suggests that the ST test, but not the TT test, generates on court pressures with which the Juniors have not yet learned to cope.

In the second group of studies the stringency and rigor of the 2 tests were exponentially elevated by changing (1) the tested Players to Professional Squash Association (PSA) Players and by (2) the computer programs driving the arrhythmicity and explosivity of the drills (2, 3). The studies included the top ranked PSA Pro in the world (World #1) in the years of the study (2004/2005), other PSA Pros as well as modifications of the computer programs to reflect ‘deep gets’, sounds and lights of Pro tournaments (i.e. graded tests). In results from both the graded Squash Specific Test (ST) and the graded Treadmill Test (TT), with some exceptions, (reporters: V–O2, V–CO2 and breathing frequency values were higher at maximal loads (Te), most reporters including the heart rate (HR), the %V–O2max, at Ventricular Threshold (VT) and the respiratory compensation point (RCP) were not significantly different for the 2 tests with the PSA Pros. As with the Juniors, results of parameters determined in ST correlated better than those determined in TT, with known physiological performances of the PSA Pros recorded in the lab and in tournaments (2, 3). In this case there was a much smaller difference in the on court pressures with which the Pros could not cope.

There is a key result from these 3 papers (1 - 3) ! The Juniors, unlike the Pros, showed significantly lower performances in the ST than in the TT tests. All things being equal the better developed ability for energetic conservation of movements may be the defining reason. However, the more intrinsic, evolutionary, developmental, genetic and neuroscientific contributors must also play some role!
This result emerged despite the higher pressures of the graded ST and TT tests to which the Pros were subjected. Is this solely due to strength conditioning? Or do these differences also reflect those traits such as fluidity of moves and conservation of energetics that Coaches and Players recognize and now Robotics and the Neuroscience studies of Spinal Cords reveal and confirm?

As it they are established as contributing factors from the above studies on Robotics Measurements and Spinal Cord Motor Neurons, this difference between Pros and Juniors in ST versus TT test results could be attributed to 3 additional differences that were previously unknown. They are the energetics acting as modulators of movements (e.g. stride lengths), the ability to adjust movements in general (e.g. stride lengths) to conserve energy (6, 7) or alternatively in the development of Spinal motor neuron system (8, 9).

These new results have emerged from work done by Dr. J. Maxwell Donelan and his Group being published in Current Biology (Humans Can Continuously Optimize Energetic Cost during Walking ) . The same work is also summarized by correspondent Meghan Rosen in Science News (Humans adjust walking style for energy efficiency; Robotic exoskeleton studies reveal body’s ability to quickly economize movements) . Finally the work done on Spinal Cord motor neurons regulating movements independently of the brain were done by Dr. Pfaff and his co –workers and reported in the Journal Neuron (http://www.ncbi.nlm.nih.gov/pubmed/26335645). The same work was summarized by correspondent Janelle Weaver PhD, reporting in the Journal BioTechniques (Walking circuits in the Spinal Cord, http://www.biotechniques.com/news/Walking-Circuits-in-the-Spinal-Cord/biotechniques-360552.html?autnID=340169#.Vf2nBX0aOH8)..

References:
Steininger, K., Dr. med. And Wodick, R.E., Prof. Dr. Dr. rer . nat , Sports- Specific Fitness Testing In Squash, Brit J. Sports Med. 21(2): 23 -26, (198&) http://bjsm.bmj.com/content/21/2/23.full.pdf+html

Girard, O., Sciberras, P., Habrard, M., Hot, P., Chevalier, R., Millet, G.P., Specific incremental test in elite squash players; Br J Sports Med; 39: 921 – 926 (2005). http://bjsm.bmj.com/content/39/12/921.full

Girard, O.,Sciberras, P., habrard, M., Hot, Chevalier, R., Millet, G.P., Specific incremental test in elite squash players, Br J Sports Med 39: 921 – 926 (2005), http://bjsm.bmj.com/content/39/12/921.full.pdf+html

Barrington, J. Barrington On Squash – The definitive coaching book by a world champion, 2nd Edition, Publisher Pan Books, Cavaye Place, London, SW10 9PG (ISBN-0 330 24670 4) (1976), http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Dstripbooks&field-keywords=Barrington+On+Squash

Ferez S. Nallaseth, PhD; A Patient’s perspective on open heart surgery from diagnosis and intervention to recovery, http://pharmaceuticalintelligence.com/2015/05/10/a-patients-perspective-on-open-heart-surgery-from-diagnosis-and-intervention-to-recovery/
Jessica C. Selinger,1 Shawn M. O’Connor,1 Jeremy D. Wong,1 and J. Maxwell Donelan1,* Humans Can Continuously Optimize Energetic Cost during Walking
mdonelan@sfu.ca; Current Biology http://dx.doi.org/10.1016/j.cub.2015.08.016

Meghan Rosen; Humans adjust walking style for energy efficiency : Robotic exoskeleton studies reveal body’s ability to quickly economize movements, Science News, September 10, 2015 https://www.sciencenews.org/article/humans-adjust-walking-style-energy-efficiency?utm_source=Society+for+Science+Newsletters&utm_campaign=0ab8ffb376Editors_Picks_Week_of_September_7_2015&utm_medium=email&utm_term=0_a4c415a67f-0ab8ffb376-104520393

Janelle Weaver, PhD, Walking Circuits in the Spinal Cord, BioTechniques, http://www.biotechniques.com/news/Walking-Circuits-in-the-Spinal-Cord/biotechniques-360552.html?autnID=340169#.Vf2nBX0aOH8

Hinckley CA, Alaynick WA, Gallarda BW, Hayashi M, Hilde KL, Driscoll SP, Dekker JD, Tucker HO, Sharpee TO, Pfaff SL. Spinal Locomotor Circuits Develop Using Hierarchical Rules Based on Motorneuron Position and Identity. Neuron. 2015 Sep 2;87(5):1008-21. doi: 10.1016/j.neuron. 2015.08.005. http://www.ncbi.nlm.nih.gov/pubmed/26335645