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Factors account for differences in responsiveness

2 parts. 1st part is to Answer the 3 questions below.

2nd part is to respond to the 5 post below. (100-200 words each post)

Due Saturday July 6, 2019



1. Explain what factors account for differences in responsiveness of individuals to the same training program. (100-200 words)

2. A coach insists that a single activity mode improves aerobic capacity for all physical activities requiring a high level of aerobic fitness. Give your opinion regarding the potential effectiveness of single-mode exercise to produce generalized cross-training effects. (100-200 words)

3. After reading the article on programming, discuss the changes you would make in your current rehabilitation / performance programs to enhance your programming skills. (100-200 words) (Article is in the link listed below)


1. Delania Adams (Post 1)

After reading this article I found something very interesting that I never realized before. The article explained how excessive forces used by the elbow at a young age can have an effect on the elbow in adulthood as well. In adults excessive forces often lead to failure in ligaments and tendons, however, children use their secondary open growth plates and apophyses (Hutchinson & Wynn, 2004). A child’s growth plate will yield before it allows the excessive forces to cause failure within their ligaments or mature bones (Hutchinson & Wynn, 2004). Excessive force and overuse of the elbow of a child can lead to chronic issues as well was adaptational issues within the bones due to the elbow not being fully developed (Hutchinson & Wynn, 2004). I’ve never personally worked with a child who has suffered from an elbow injury, however, I have dealt with adults who have suffered from an elbow injury. My thoughts and opinions about the 6 stages of throwing from reading the article can cause excessive overuse of the elbow on a young child. The 6 stages of throwing consist of the windup, stride, arm cocking, arm acceleration, arm deceleration, and follow-through (Hutchinson & Wynn, 2004). During the windup stage, the forearm is slightly pronated and the elbow is flexed (Hutchinson & Wynn, 2004). During the stride and arm cocking phases the elbow is slightly extended with minimum forces crossing the elbow (Hutchinson & Wynn, 2004). During the full arm cocking stage, the forearm in fully pronated and the elbow is extended with the shoulder in external rotation (Hutchinson & Wynn, 2004). In the acceleration stage, the ball is being released and the elbow is extended and flexed (Hutchinson & Wynn, 2004). Watching my nephew began playing baseball and learning the proper throwing technique after reading this article give me some concerns. My concerns are mainly targeted to him overusing both his shoulders and his elbow at an early age due to his love for the game of baseball. If I see a child teaching their child the throwing phase I would recommend the parent knowing the proper technique of ball throwing, I would also recommend the parent being able to explain to those child ways that could make their elbow hurt as well as their shoulder. I would recommend to a parent the older a child gets in order to prevent future injuries to teach them the biomechanics of throwing. My thoughts on kids who play little league baseball from a pitcher standpoint, I believe the children should have an allowed number of pitches per game they are allowed to pitch. I think the very first throw they should learn should be the underhand pitch, with a different pitcher every game so that the children will not overuse their elbow and shoulder joints. 

2. Josh Young (Post 2)

I appreciated how the article really broke down each of the phases of throwing, from the description of each phase to the biomechanics of each phase. I also thought it was interesting to see the progression of throwing mechanics through the lifespan. I have two young cousins who were learning how to throw when I took “Motor Development through the Lifespan” in my undergrad degree. The information from the class was fresh on my mind and I got to watch first-hand how kids progress with the throwing motion. The article mentioned that kids who start the throwing motion with the torso parallel, or facing the target are not likely to experience injury because not enough force can be generated (Hutchinson & Wynn, 2004). When I stop and think about it, that actually makes a lot of sense. Due to the amount of torque and force that is produced through the torso when throwing, the elbow is extended with a whip-like motion (Escamilla & Andrews, 2009). If you were to take away the force that is generated from the lower body and torso, then the amount of force that is transferred to the elbow is significantly decreased, which decreases the likelihood of injury. I was also intrigued by the findings of the biomechanical analysis between the youth, high school, collegiate, and professional pitchers. In terms of biomechanics, there was really no difference, except for velocity which increases as the athlete’s body grows and becomes stronger (Hutchinson & Wyn, 2004). To get to that point, it all goes back to learning the basics. Learning to throw is a process, it’s not something that can be learned efficiently overnight. It takes time for the entire body to learn to work together and synchronously. Two words that are used throughout the article that I completely agree with “sequence” and “coordination”. The throwing motion is a coordinated sequence of events that involves the lower body, the core, and the upper body. I’ve been around pitchers who did not see any point in doing “leg day” at the gym because they thought it was pointless to train their legs when their arms are doing all the work. Personally, I feel like having a strong lower body and core is more important than having a strong shoulder/arm. Hutchinson and Wyn (2004) even say that pitchers who do not have a good push-off (lower body) or are lacking torso rotation (core) may experience elbow pain because the body has to make up that lost force production somewhere along the kinetic chain. Throwing starts with the push-off and core rotation. Those things are the foundation of throwing hard, so if those areas are lacking, then throwing becomes much less effective and increases the chances of injury. I played baseball for several years, and though I never really had a desire to pitch, I always wanted to throw a curveball. My dad wouldn’t let me though for fear of me hurting my elbow, like the article mentioned. Anyone have experience with throwing a curveball at a young age and how that turned out for you?

3. Emily Blakemore (Post 3)

My experience and exposure to those who have experienced elbow injuries as a young athlete is slim to none.  For that reason, this article was very interesting to me.  In general, young athletes shouldn’t be pushed to extreme measures.  The focus should be on having fun while also developing skills.  That said, some young athletes are eager to go above and beyond.  When it comes to pitching in baseball, coaches should be ready to keep that eagerness in check so the young athlete does not damage their still-developing body.  As the article stated, excessive forces cause damage to open growth plates.  “Overuse can lead to adaptational or chronic pathological changes in the skeletally immature elbow” (Hutchinson & Wynn, 2004).  This is why it is important to limit the number of pitches in young athletes.

I also found the mechanical developments of throwing in children to be informative.  As they mature and grow, they learn to coordinate their movements and position their bodies to create more force and velocity in their throw.  I appreciated the point made that “’throwing like a girl’ represented simply an immature throwing mechanic and not a specific gender-related anatomic or physiologic finding… The concept that gender alone causes an abnormal throwing mechanic should be discarded” (Hutchinson & Wynn, 2004).  As young athletes’ bodies mature, develop, and grow at different ages and at different rates, it is important for coaches to be aware of these physical changes and adapt their enforcement of pitch counts appropriately; “the physis appears to be at increased risk of injury during active phases of growth.”

I like that the article examined the different types of pitches and their associated elbow pain in young athletes.  They found that rather than the long-believed curve ball causing more elbow pain, it was actually the slider that had a significant relationship to elbow pain.  And of course with every sort of exercise and movement, it was found that those who had poor technique had a higher pain and injury rate than those who used proper technique. 

To protect these young kids from damaging their developing bodies and muscles and to save them from experiencing pain, it is crucial to focus on proper biomechanical developments, and keeping to the limited pitch counts recommendations.  “Children should not be allowed to throw as hard as they can until a mature throwing mechanic is documented” (Hutchinson & Wynn, 2004).  I like how the article specifically addressed the eagerness of Little Leaguers and their parents to push the limits thinking that their dreams of playing in the big leagues will be achieved if they disregard the precautions set in place.  The quote that made me smile was, “No Little League All-Star pitcher has become a professional level pitcher.”  The child’s safety and health should be top priority, and a reality check by parents should be made. 

4. Kendra c (Post 4)

I played softball when I was younger and had a few siblings that played baseball as well. We were taught from a young age on how to throw properly so it kind of came natural to me. I have never experienced any injuries with my elbows and nor did my brothers. If I were to recommend to a parent who is trying to teach their child to throw, I would talk with them about the following. I would tell them that the best time to correct improper biomechanics, and thereby prevent elbow injury and pathology, is at the beginning of a pitcher’s career, which usually starts during youth or Little League baseball. The two primary targets of intervention are overuse and technique. Elbow pain in young baseball pitchers is associated with many factors, including age, weight, height, number of pitches thrown during a season, satisfaction with performance, lifting weights, and playing outside of the league. Age and the timing of the child’s growth spurt appear to be important factors, because the physis appears to be at increased risk of injury during active phases of growth (Hutchinson & Wynn, 2004). There are six stages of the pitching motion that include the windup, stride, arm cocking, arm acceleration, arm deceleration, and follow-through. I feel like the best approach with younger kids who are first learning to throw is to play games that just involve throwing with them. I think this helps with coordination without offering that child instructions and helps them develop their muscles memory over time. When the child starts to get older is when you should start basic throwing education to that child. When you are teaching them at an older age you just need to provide guidance and not overpower them with correcting their technique. The more repetitions the more they can improve their throwing.

5. Kaityln Keith (Post 5)

Something I thought was really interesting was how an athlete can be skeletally immature due to dynamic changes occurring during the developmental phases of youth. While a child is growing you have to make sure that you are allowing the bones to lengthen with physeal growth. However, “the forces and torques of throwing with open physes have been associated with adaptational changes in the growing bone (Hutchinson, M. R., MD, & Wynn, S., MD. (2004)).” Although each segment of the kinetic chain matures at its own pace allowing athletes to make continuous and subconscious modifications to account for the changes going on in the young athlete while still allowing him to perform to his best abilities.

Specifics regarding a skeletally immature thrower:

            “Although the fundamental concepts of throwing biomechanics apple to developing elbow, a number of factors make it difficult to directly translate the forces and specific mechanics of the adult thrower to the skeletally immature thrower (Hutchinson, M. R., MD, & Wynn, S., MD. (2004)).” Throwing mechanics depend on the age, weight, height, stride length and the length of the kinetic segment. During this time I think it is important to observe the athlete at this young age to see where they are pulling the force from. Some of the force can come from the trunk, the humerus and the forearm. One of the major steps while developing a young athlete is to begin the sequence with their torso facing perpendicular to the target. By teaching them this it will allow for a more mature development in their windup, stride, cocking, acceleration and follow-through. “In each stage in which the child begins parallel and not perpedencular to the target, it is difficult if not impossible to create enough torque and force development along the kinetic chain to negatively affect the ligaments or growth plates (Hutchinson, M. R., MD, & Wynn, S., MD. (2004)).”

Personally, for me after gaining this knowledge this is exactly how I would want to train any young athlete who was a pitcher. Working in a clinical setting where athletes fly in and out with different injuries I have seen more pitchers than I have any other position. Some of them come in with elbow pain or back pain. Most of this starts at the hips. If their hips are not mobile or have any stability this will cause problems elsewhere because they will start to pull force from different parts of their body opposed to their trunk because of lack of movement and proper rotation of the trunk.

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