Healthy Debate

In Motor Development, we are discussing how different constraints, such as individual, environmental, and task interact to influence movement and the development of movement. An interesting case to examine is that of Oscar Pistrorius. If you are not familiar with Pistrorius, he is a double leg amputee from South Africa that nearly qualified for the 2008 Beijing Olympics. He has shattered all Para-Olympic sprinting records. There was much debate, and still is, in the track world and the academic world about whether Pistorius should be allowed to compete against able bodied competitors. There are many that claim he has an unfair advantage due to the prosthetic legs, and others that claim he does not have an advantage and should be allowed to compete. This article examines both sides of the issue. Without going into too much detail, one of the arguments against Pistorius is that his prosthetic legs are less massive than the legs of able bodied competitors. One of the key determinants of running speed is stride frequency, or how fast the runner can place his or her foot on the ground, exert force, and swing the leg back through and touch the ground again. A less massive leg would require less force to accelerate than a more massive leg, which would increase stride frequency. One of the arguments for Pistorius is that the prosthetic legs put him a major disadvantage at the start of the race. As you can see in this video (Pistorius is in lane 5), he loses considerable ground at the beginning of the race because the design of his prosthetic legs cause him to stand up quickly, which results in more vertical force than horizontal force. As you can see, there are arguments on both sides of the coin. In this instance, there probably is not a right or wrong answer, but from a biomechanical and developmental perspective, it is good to debate.

My take on P90X

There are many workout programs on the market today, and many of them promise results in as little as 10 minutes a day, 3 days a week. Needless to say, I am skeptical of most of these. If you watch any amount of television, then you have undoubtedly seen the infomercials for P90X. A few months ago, my wife suggested that she would like for us to try and complete the P90X program together. I did some research on it, and since I had grown tired of just going to the gym and doing the same routine 4-5 days per week, we decided to give it a try. All you need is some space, dumbbells, pull-up bar, and yoga mat. We completed the 90 day program a few weeks ago and I have started on the P90X Plus program. I'll post some information about our experiences and opinions below.

1. This is an intense program, and you have to be dedicated to finish it. It requires a little over an hour of your time 6 days per week, and some days you may just not feel like working out. But, once you start the program, or pretty much any exercise program, you will likely be motivated to complete it. That said, with P90X, it requires a lot of time and effort, but we saw very positive results, such as strength gains, flexibility improvements, and an increase in cardiovascular endurance. It is not a "gimmick" workout program.
2. The workouts target every major muscle group in your body, which is good if you are a person like me that rarely ever concentrated on his lower body at the gym.
3. You can modify the workouts. Based on your fitness level and goals, you can change the number of repetitions of an exercise you perform, the amount of weight you use, etc. This is extremely helpful for those starting at a lower fitness level or not wanting to "bulk up."
4. The Yoga and flexibility workouts were extremely beneficial for me. Before starting this program, my flexibility was terrible. I knew it was terrible and knew that I needed to spend more time performing flexibility exercises, I just wouldn't do it on my own. Well, since this was part of the program, I was forced to do it. My hamstring flexibility was awful before beginning, I could probably only reach down about halfway between my knees and foot in either a standing or sitting position. After completing the program, I can bend over and put all 5 fingers on the floor, and I can also touch the bottom of my feet in a seated position.
5. We really enjoyed the workouts, they didn't seem to last an hour and we had a lot of fun. The workouts also have good warm-up and cool down periods.

Now, let me offer a few words of caution about the program.

1. This is an intense program, so you should be in relatively good shape before beginning. If you have any questions about whether or not to start, a visit to your physician is probably a good thing.
2. Tony Horton uses the terms "muscle memory" and "muscle confusion" during the infomercials and workouts. I've already blogged about the fallacy of muscle memory, and muscle confusion also does not exist. While a positive of the program is that you perform different exercises and routines, this does not result in muscle confusion. I'll have to do a blog post on muscle confusion in the near future.
3. Depending on what your goals are, this program may not be for you. If you are looking to make larger strength gains and really bulk up, or are just looking to lose a few pounds, then I wouldn't recommend P90X.

The most important thing to remember is to find some form of exercise that you enjoy doing that incorporates strength training, flexibility, and a cardiovascular component. It doesn't have to be P90X or some other fancy exercise routine. The best thing you can do for your long term health is to start moving!!

Impressive Resume

I wanted to take a few minutes to brag on a very successful coach in my family, my uncle, Larry Knight. This past Sunday, he was the manager for the East team in the Aflac All-American high school all star game, which was played at PETCO park in San Diego and broadcast nationally in High Definition. When he's not coaching in all star games, he is the head coach at Sumrall high school in south Mississippi. He has compiled a very impressive resume at Sumrall, winning 3 straight state championships, including going undefeated in 2009 and only losing one game this past season. Sumrall also set the Mississippi state record for consecutive victories this past season. Larry also won 4 state championships while coaching at Hattiesburg high school. I may be a little biased, but I think he has to be considered among the best coaches in Mississippi baseball high school history. I also have to mention that Larry's son and my cousin, Austin, is also a really good catcher for Sumrall. They have a great chance to win another championship in 2011.

Probable End of an Era

I was saddened by the news today that Chipper Jones tore the ACL in his left knee and will need reconstructive surgery. Now, although I am a huge Cardinals fan, I watched many a Braves game growing up because my mother loves the Braves. I also got to see Chipper play in person several times in Atlanta when I was doing my graduate work at Auburn. He is probably one of the best switch hitters to ever play the game, and I'm sure this is not how he wanted to end his career.

I've watched the video of the injury several times and there is really not a good shot of the injury. He jumps up in the air to make the throw to first, and tears his ACL when he lands on his left leg. It appears his left knee is almost fully extended, and there is some rotation of both the upper and lower legs as well. What likely happened to his knee can be seen in the picture above. This puts a tremendous amount of stress on the ACL and can cause a tear. Hopefully the surgery will go well and he can make a full recovery.

To Stretch or Not to Stretch

I apologize for the length of time between blog posts. I spent most of June traveling and have been busy with summer classes this past month. One of the places I went in June was to Philadelphia, PA, for the National Athletic Trainers Association annual meeting and symposium. I did a presentation on some of my ankle research and got to hear many presentations from leaders in our field. One of the talks was on stretching. There is debate in the scientific field and athletic community about the importance of stretching, when you should stretch, how much you should stretch, etc. The big questions are: does stretching improve or hinder performance, and what is the effect of stretching on injuries? I'll go through the questions now with my opinion and what was discussed at the conference.

1) What is the effect of stretching on performance? Most athletes do some type of stretching before practice or a game. There has been some debate in the literature about whether or not stretching right before a competition, especially one involving speed, will hinder performance. Basically, one theory is that stretching will make you slower. There is some evidence to support this, and some evidence that does not. The panel said that there is not enough evidence yet to support either theory, but that for most athletes, a dynamic stretching routine (one where the body is moving) is preferred over static (being still and holding a position) before practice or a game.

2) What is the effect of stretching on injuries? Another question is whether or not increasing flexibility will reduce or limit the potential for injuries. Again, there is not enough research to support the notion that increased flexibility will reduce the number of injuries. It has been established that you lose flexibility after an injury, and that regaining this flexibility is a key component of the rehabilitation program. It is also known that flexibility imbalances between the extremities, just like strength imbalances, may lead to injury. But, for example, there is no concrete evidence that says if you do not have this amount of hamstring flexibility, you are more prone to a hamstring strain.

So, to sum this up and give you my opinion, stretching and flexibility should be an important component of any exercise or rehabilitation routine. I think it is better to do more dynamic stretches before you exercise, practice, or compete, and static stretching should be done after a workout or if the goal is to increase range of motion. There is research to support that tight hamstrings and hip extensors can lead to low back pain, so it is essential to stretch these muscles. Until more research is conducted, the other questions cannot be answered.

Muscle Memory: Fact or Fiction?

A popular term that is tossed around among sportscasters and fitness professionals is "muscle memory." The basic premises behind muscle memory is the more you practice a skill, the better you become at it because the muscle "remembers" what to do. There is no doubt that proper practice yields improvement in performance, strength, coordination, etc. However, these changes are not due to muscle memory. There is no memory structure within the muscle itself, therefore, the muscle cannot remember or forget to do things. Every single muscle fiber is connected to the nervous system by the way of a motor unit. In order for a muscle to fire or contract, a signal must be sent to the fibers from the nervous system. The "memory" part is in the nervous system, and more specifically, in the brain. If you remember the first time you attempted to hit a baseball, shoot a basketball, ride a bike, etc., you were probably clumsy, uncoordinated, and had little success. Over time, you probably saw improvement. When we perform a skill we have little to no experience with, the nervous system does not know which muscles to recruit (activate), how many muscles to recruit, how frequently to recruit the muscles, and when to turn the muscles off. As we practice the skill, the nervous system begins to learn and remember, and recruits only the muscles needed to perform the skill, and at the right frequency and intensity. The nervous system also learns to turn off muscles that are not needed to perform the skill and would hinder performance. So, the theory of muscle memory is actually a complex process that involves both the nervous system and the muscular system. But, there is no memory structure within muscle, so the term muscle memory is fiction.

Perfect Game

This past Sunday, Dallas Braden, of the Oakland A's, threw a perfect game against the Tampa Bay Rays. There are many amazing feats in athletics, but to me, a baseball purist, throwing a perfect game may just top them all. There have only been 19 perfect games in the 100 year plus history of Major League Baseball. A perfect game requires a complete team effort. Twenty seven hitters are all retired without any of them reaching base. The pitcher cannot make any mistakes, such as walking a hitter, hitting a batter with a pitch, or leaving a pitch out over the middle of the plate that is likely to be crushed for a base hit. It also requires a tremendous effort on the part of the defense, to commit no errors, and likely make a great play or two to preserve the perfect game. Braden also accomplished this feat against the Rays, who at the time had the best record in baseball. A perfect truly is a rare and remarkable feat.