written by Scott K. Lynn, PhD
Follow on Twitter @ScottKLynn_PhD
Dealing with injuries is an inevitable part of any sporting or physical activity. Some injuries are an inherent part of sports/physical activity participation and are not preventable, while others develop because of inefficiencies in how we move and can sometimes be prevented with proper training and movement pattern correction. Shirley Sahrmann, in her 2002 textbook, suggests that there are two basic models that can explain the development of injury 1. These two models are the kinesiopathologic (movement injury) and pathokinesiologic (injured movement) models. In the pathokinesiologic model, the pathology (or injury) comes first. This model is initiated by an acute event or some kind of inherent abnormality (anatomical, physiological, etc.) within the individual, and therefore would be difficult (if not impossible) to prevent. An example of such an injury would be a hockey player getting hit in the foot with a slap shot and breaking a bone in their foot. This type of injury was caused by an acute event and therefore would fall under the pathokinesiologic model. There may be an argument that this could have been prevented with better protective equipment, but even with the best equipment, these types of injuries will still occur. Another example of a pathokinesiologic injury would be a tennis player who develops shoulder pain that is diagnosed as subacromial shoulder impingement due to a hooked acromion process. This shoulder pain is a result of an anatomical abnormality and would therefore fall under the pathokinesiologic model as well. For both these types of injuries, it is important that the injured/abnormal tissues are corrected through whatever means necessary (surgery, immobilization, etc.) and then the individual is given adequate time to allow inflamed tissue to heal before returning to activity. In these types of injuries, it is also important that the movement patterns of the individual are checked before they return to activity, as the pain they experienced due to their pathology may have caused compensation in their movement patterns which could lead to injury elsewhere once they return to activity. For example, breaking a bone in your foot and having to stay off it for several weeks could alter the functioning of your intrinsic foot musculature. When the bone in the foot heals, this muscular dysfunction needs to be corrected before the athlete returns to full activity. If it is not, this could lead to excessive foot pronation and hence, knee valgus collapse during movement which could result in the development of knee pathology (patellofemoral pain syndrome, IT band syndrome, ACL injury).
In the second injury model, the kinesiopathologic model, it is the movement that precedes the pathology. Because this type of injury is related to the way in which the individual moves, these are thought to be much more preventable than the pathokinesiologic type of injury. Sahrmann believes that kinesiopathologic injuries are caused by repeated specific joint movements or sustained postures; therefore, in order to prevent these types of injuries, one must ensure that there is sufficient variety in joint movements and postures. This theory is supported by a recent prospective injury prediction study that we just completed on NCAA division I track and field athletes and presented at the recent American College of Sports Medicine (ACSM) Annual Meeting in Orlando 2.
This was a prospective analysis that examined the predictive nature of the Functional Movement Screen (FMS) – see Figure 1 below. The FMS is a tool this is widely used to assess the quality of human movement patterns and their underlying muscle activation patterns. It consists of a battery of 7 tests used to identify functional limitations and contralateral asymmetries. Each test is individually scored using a numerical scoring system ranging from 0 – 3, where a higher score indicates a more efficient movement. The FMS has been shown to be able to prospectively predict injury in several different groups of athletes. These include professional football players 3, military trainees 4, and female collegiate basketball, soccer and volleyball players 5. All of these studies found that those with a lower score on the FMS were more likely to sustain an injury. However, a more recent study on a more diverse population of NCAA division I athletes (basketball, cross country, golf, football, track & field, tennis, volleyball, soccer, swim/dive) found no association between FMS score and injury 6. Clearly more work need to be done
Our recent study discovered some extremely novel results that were contrary to the studies that had been done previously. Our data showed that those runners who scored higher on the pre-season FMS were MORE likely to be injured. It was determined that for every 1 point a runner scored higher on the FMS, they were 1.5 times more likely to experience an injury during that season 2. We believe that the reason for our aberrant findings may have to do with a variable that is not directly measured by the FMS, movement variability.
Dr. Joe Hamill has suggested that there is an optimal window of movement variability in which an athlete must function to remain healthy and injury free 7. Therefore, too much or too little variability in movement can lead to an injury (Figure 2). Although it is not directly measured by the FMS, it can be hypothesized that those who score high on the FMS would have very consistent movement patterns with low movement variability, while those who score low on the FMS would have more variable movement patterns with high movement variability.
Figure 2. A schematic demonstrating the proposed relationship between high and low movement variability and injury risk (taken from Hamill et al., 2012 7)
We believe there are two ways we can get variability in our movements. The first is the amount of variability in our movement patterns and the second is the type of sport/activity that we regularly participate in. All of the studies that have shown that a higher score on the FMS resulted in a decreased injury risk used subjects who participated in activities/sports that are extremely variable in nature 3,4,5. The subjects in these studies were military trainees or football, basketball, soccer, volleyball players. All of these individuals regularly perform whole body multi planar motions as part of their daily practice and competition schedule. Therefore, it can be hypothesized that those who score high on the FMS would remain healthy as the low movement variability they get from their movement patterns counteract their extremely variable sports/activities and bring them into the optimal level of variability, thus remaining healthy. Whereas, the subject tested in our current study (NCAA track athletes) all perform an activity that has an extremely low amount of variability, running. Therefore, those athletes who scored high on the FMS have low amounts of variability from their sport/activity and also low amounts of variability from their movement patterns, resulting in an insufficient amount of movement variability and injury. The results of Warren et al. 6 can be explained by the fact that their subject pool included both athletes who play sports with high variability (basketball, football, soccer, volleyball, tennis) and those who play sports with low variability (cross country, golf, track & field, swim/dive). This mixture of athletes from high and low variability sports could be the reason the FMS did not predict injury at all in this population.
So how can this information be useful to those who train and work with golfers? First of all, golf is a sport that has an extremely low amount of inherent variability; therefore, in order to keep golfers healthy and injury free, we must somehow introduce increasing level of movement variability into their practice/training routines. Some possible suggestions in terms of how this can be accomplished may include having golfers hit balls on the range and/or play golf the opposite way (i.e. right handed golfers hitting balls left handed). Developing skill at executing a golf swing in the opposite direction may help in injury prevention by may also be useful if the player is ever presented with a situation during a tournament where hitting the ball their normal way is impossible (i.e. their ball is up against a tree/fence). Another suggestion that could introduce smaller amounts of variability into their movements would be to have golfers constantly altering the club used and type of shot they are hitting on the range (high, low, draw, fade, etc.) rather than constantly trying to produce the same ball flight, with the same club, over and over again with successive swings.
We also may be able to introduce variability in golfers movements by altering the training they do off the golf course. Since the golf swing involves a lot of transverse plane (rotational) movements, it may be wise to emphasize sagittal and frontal plane movement in the gym/off the course to increase the variability of their movement and avoid injury. For example, many golfers would spend their practice days hitting balls on the driving range for a couple hours and then playing a practice round before heading to the gym for a workout. After completing several hundred golf swings, perhaps we should avoid more rotational type movements (i.e. lateral medicine ball throws) in the gym and focus more on sagittal (i.e. squats, lunges, etc.) and frontal plane (i.e. slide board) work. The rotational work in the gym is important to help with the golfer’s performance; however, perhaps this should be saved for the off season and/or days when the golfer is not working on their swing. On these “off” days, golfers could also introduce variability in their training by doing extra repetitions/sets of rotational movements in the opposite direction of their golf swing.
The research has begun to suggest that movement variability may be an important factor in avoiding injury. Although this is the case, it is important to note that the above applications in golfer training are simply hypotheses. Much more research is needed to investigate the concept of movement variability and how it can be appropriately introduced into training and practice sessions in order to avoid injuries and keep golfers healthy and able to perform at the best of their abilities.
If you have any questions/ideas/comments/suggestions or would like to discuss this concept further, feel free to contact me at firstname.lastname@example.org or @CSUFGolfBiomech on Twitter.
- Sahrmann SA (2002). Diagnosis and Treatment of Movement Impairment Syndromes. St. Louis, USA; Mosby, Inc.
- Lynn SK, Padilla RA, Tsang KKW, Noffal GJ (2014). Prospective injury prediction using the Functional Movement Screen (FMS) in Division I runners. 61st ACSM Annual Meeting. Orlando, FL.
- Kiesel K, Plisky P, Voight M (2007). Can serious injury in professional football be predicted by a preseason functional movement scree? North American Journal of Sports Physical Therapy. 2(3):147-158.
- Lisman P, O’Connor FG, Deuster PA, Knapik JJ (2013). Funtional Movement Screen and aerobic fitness predict injuries in military training. Med Sci Sports Exerc. 45(4): 636-643.
- Chorba R, Chorba D, Bouillon L, Overmyer C, Landis J (2010). Use of functional movement screening tool to determine injury risk in female collegiate athletes. North Amer J Sports Phys Ther. 5(2): 47-54.
- Warren M, Smith CA, Pinson R, Chimera NJ (2013). Functional Movement Screen is a poor predictor of injury in Division I athletes. 60th ACSM Annual Meeting. Indianapolis, Indiana.
- Hamill J, Palmer C, Van Emmerik R (2012). Coordinative variability and overuse injury. SMARTT: Sports Medicine, Arthroscopy, Rehabilitation, Therapy & Technology, 4(1), 45-53.