AC Sprain

I apologize for the delay between blog posts. It's been a hectic couple of weeks. Keeping with the theme of discussing current football injuries, I thought it would be good to talk about AC sprains. The acromioclavicular joint is the articulation between the distal end of the clavicle and the acromion process of the scapula. It is a critical link in proper functioning of the shoulder complex. Anytime you move your shoulder, the clavicle moves with it. The common term for an AC sprain is a "seperated" shoulder, because of the seperation that occurs between the two bones. This can be a very painful and debiliating injury, especially for a quaterback. This injury commonly occurs from falling on an outstretched hand, or by landing direclty on the joint. In Sam Bradford's case, he landed directly on the AC joint during the BYU game, and again this past weekend against Texas. Because the AC joint is very superficial, it is not easy to protect with padding. It is even harder for a quarterback to rehabilitate from this injury because of the throwing motion. Depending on the severity of the injury, players can be out anywhere from a few days to a few months, if surgery is required to repair the ligaments.

Fun Fact: The Coracoacromial ligament actually connects to the same bone, the acromion process and coracoid process of the scaupula. Almost all ligaments connect two different bones together.
Fun Fact 2: One way to test for damage to the AC joint is to press down on the clavicle. If the clavicle "pops up" more than the non-injured side, then the person may have an AC sprain. This popping up of the clavicle is referred to as the "piano key" sign.

To play or not to play

Unless you live in a cave, you have probably seen the hits that lead to Tim Tebow suffering a concussion two weeks ago against Kentucky. Tebow actually took two hits to the head on the play, the one pictured to the right, and another to the back of the head when he hit the leg of his own lineman. Tebow was knocked unconscious and spent the night in a Kentucky hospital. The raging debate this week is whether or not Tebow should play against LSU Saturday night. Many times, commentators refer to a concussion as someone having "their bell rung." Well, that does not really describe what a concussion is, and the National Athletic Trainers Association (NATA) discourages the use of words such as "ding" and "bell rung". According to Arnheim and Prentice, a concussion, also know as a traumatic brain injury (TBI), is defined as "a clinical syndrome characterized by immediate and transient posttraumatic impairment of neural functions-such as alterations of consciousness, disturbance of vision, loss of equillibrium, etc., due to brain stem involvement." The majority of concussions do not involve loss of consciousness, but Tebow's did. Now, Tebow will undergo numerous tests to measure his cognitive function, equillibrium, physchological function, etc., to determine if he can play. These scores will be compared to baseline scores taken before the season started. If he passes all these tests and scans of his brain come back normal, he will likely be cleared to play. I do believe the medical staff at Florida will not clear him to play unless he passes all of these tests. The next question is, should he play, even if he is cleared? While there has been some good research done on concussions, the long term affects are still unknown. It will be a tough decision, and one I am glad I don't have to make.

Motor Milestones

We have been discussing recently different motor milestones and how infants progress through these milestones. For example, an infant must first be able to hold his or head up before they can crawl, and he or she must be able to stand without support before they can walk. There is an average age range that most infants reach these milestones by. We must remember, however, that these are just average ranges. I think sometimes we place too much emphasis on "Is my child normal?" We have to remember that these average ages are just that, averages. That means some children will reach these milestones faster and some slower than others. Does that mean there is something wrong with the child? Not necessarily. The average walking age is around 12 months. But, some children will begin walking as early as 9 months, and some will not walk until 15 months. The other thing to consider is that the individual constraints of the infant interact with the environment and task to influence how and when we move. So, an infant that has developed the appropriate muscular strength and is frequently placed in an environment that encourages her to walk will more than likely begin walking sooner than a child not placed in that environment.

"High" Ankle Sprains

We have been discussing the ankle in class, and one of the topics has been the "high" ankle sprain. The most common type of ankle sprain is the "lateral" ankle sprain, which damages the ligaments on the outside of the ankle that connect the talus to the fibula. Most of the time when people "roll" their ankle, they sustain a "lateral" ankle sprain. While not as common, the "high", or "syndesmosis" ankle sprain, can be much more debilitating. With a "high" ankle sprain, there is damage to the ligaments of the distal tibiofibular joint, primarily the anterior inferior and posterior inferior tibiofibular ligaments, and sometimes the interosseous membrane. To sustain a high ankle sprain, the talus, through hyperdorsiflexion, is forced up between the tibia and fibula, thus separating the bones from each other. This often occurs during a pile up in football when a player lands on the back of the leg of a lineman. Recovery for a high ankle sprain is often lengthy. Every time we walk or run, the talus is forced up into the distal tibiofibular joint. In a healthy person, this is not a problem, but in a person that has damaged these ligaments, it makes recovery difficult.

Rate limiters

I apologize for the length of time between posts. We have been discussing the concept of rate limiters recently in motor development. A rate limiter is an individual constraint, or system, that holds back of slows the emergence of a motor skill. One example would be a five year old trying to shoot a basketball on a ten foot goal. He or she will lack the muscular strength to shoot the ball at a goal this high. Therefore, the muscular system would be the rate limiter. We had a really good discussion in class about how a single rate limiter of one system can affect numerous systems. As we age, certain parts of our body begin to break down. A common problem is arthritis. As people develop arthritis, which affects the joints, they tend to decrease their amount of physical activity. Well, a lack of physical activity leads to a loss of bone mass, muscle mass, degeneration of the nervous system, and many other health problems. So, what starts off as one problem eventually leads to the development of several problems. It is important to determine what rate limiter may be holding a person back and attempt to correct it before more problems arise.

Uralacher's Wrist Injury

If you follow the NFL, then you know that the Bears All Pro linebacker, Brian Urlacher, dislocated his "wrist" Sunday night against the Packers and will be out the remainder of the season after undergoing surgery yesterday. The term "wrist" only describes a general area of the body, and the exact bone that was dislocated was not disclosed in any of the press releases. The actual "wrist" is the articulation of the distal end of the radius with the proximal row of carpal bones (four bones). The most commonly dislocated carpal bone is the lunate, which is located almost directly beneath the middle finger. This bone helps hold the wrist together, and often times when it is dislocated, it must be put back into place with pins via surgery. This type of surgery requires a lengthy recovery. I was able to do some digging and Urlacher did, in fact, dislocate the lunate.

MCL "Sprain"

I blogged a couple of weeks ago about the difference between a "sprain" and a "strain." Well, during the Steelers-Titans game last night, there was a great example of a MCL sprain. The Medial Collateral Ligament is the ligament on the inside of the knee. It helps prevent the knee from "buckling" on the inside. It is frequently injured in football and injured much more frequently than the Lateral Collateral Ligament. Typically, the ligament is damaged by a valgus force, which is a force directed in the lateral to medial direction. In the above picture, the Titans player landed on the lateral aspect of the knee of Troy Polamalu, which stretched and damaged the MCL on the medial side. Football players are hit much more frequently on the lateral or outside of the knee, which causes damage to the MCL. Polamalu is reported to be out for 3-6 weeks, which would lead me to believe it is a Grade II MCL sprain. If the ligament was completely torn, as in the top picture, he would probably be out much longer, if not the entire season. With a grade II sprain, there is some tearing of the ligament, but not a complete disruption. He will likely wear a knee brace when he returns to help protect against a repeat of this injury.