Using Functional Movement Assessments to Prevent Lower Extremity Injuries

By Sami Ahmed, DPT, CES, SFMA, CMTPT

It seems like every time sports analysts talk about the most recent game—whether it’s football, basketball, baseball, college, or professional—they’re discussing another athlete’s season-ending injury. While the spectrum for the severity of injuries varies, athletes—individuals who we perceive to be in peak physical condition—often find themselves sidelined due to a vulnerability or weakness that is inherent in their body. The sports industry has also recently seen an increase in lower extremity injuries that start out minor, yet when the athlete attempts to play through the pain, the injury escalates and often requires more time off, more physical therapy, or even surgery.

Take Kevin Durant as an example. His March 2019 ankle sprain ultimately resulted in an Achilles tear in June 2019. One year later, he is easing back onto the court as part of his rehabilitation, announcing that he has no intention of returning before the 2021 season. Or Klay Thompson. He started with a hamstring strain and kept playing, which ultimately led to an ACL tear that kept him out for an entire season. It would appear that all lower extremity injuries should be taken seriously so as not to be exacerbated, regardless of how minor they may seem.

Of course, in high-energy sports, injuries cannot be avoided and prevention is never guaranteed. The good news is, diagnostic tools are available that, when used collaboratively, provide critical information about an athlete’s movement and strength. In turn, that information can be used to help develop injury prevention strategies for all, and specifically can serve as a baseline to determine if an athlete is ready to return to play after an injury.

First, Think Prevention

Injury prevention and pre-injury testing are key components of a successful sports medicine program.  While prevention comes in many forms, it is important to remember the distinction between prevention and prediction when using diagnostic tools with patients. In my practice at The Centers for Advanced Orthopaedics, I typically use the Functional Movement Screen (FMS) and the Selective Functional Movement Assessment (SFMA)¹ with my patients. Both tests are used to closely analyze specific body movements and aim to predict the likelihood of an injury and provide insights as to what an athlete needs to do to reduce this risk.

These functional assessments are used as an overall evaluation of bodily movement. When looked at as a whole, the body can be split into left and right hemispheres straight down the middle. While every human naturally has a side that is more dominant, there should be relative symmetry between the two sides in a healthy athlete. Improper or too much training in the days, months, or even years before an injury, as well as genetics and other variables, can cause asymmetry to occur in the body. While the athlete’s body may be able to handle imbalance for a while, it is likely that eventually, such asymmetry will lead to injury. A classic example of this asymmetry occurs when one knee is significantly stronger than the other. In this case, the ankle is taking the brunt of the force that imbalance creates, and could result in a tear.

Functional assessments aim to find the differences between the body’s two hemispheres and identify how movements vary on each side. This allows us to correct them and best prepare the body for an extreme athletic event—a football game, for example—and ultimately prevent instances that may result in injury – like Kevin Durant’s Achilles tear I previously mentioned.

Functional Assessments Defined

The FMS is a basic tool used to identify imbalances in mobility and stability by evaluating an athlete’s ability to perform 7 fundamental movement patterns, including

1. deep squat
2. hurdle step
3. lunge
4. shoulder mobility
5. leg raise
6. trunk stability push-up, and
7. rotary stability.

By asking the athlete to execute these extreme positions, any inherent weaknesses in locomotor, manipulative and stabilizing movements will inevitably be exposed. And, once the FMS has been completed, a healthcare professional can prescribe a customized program of exercises that will strengthen any apparent deficiencies. The FMS is intended to be a screening tool to identify opportunities to help healthy individuals build strength, develop symmetry, and ultimately avoid injury; it is not meant to be used on those who are recovering from an injury. The test is typically given by a physical therapist, personal trainer, athletic trainer, or chiropractor.

The SFMA is a diagnostic tool designed to measure pain and dysfunction from movement patterns in those with known musculoskeletal pain. Using a series of full-body movements broken down by cervical, upper-extremity, and multi-segmental movement patterns, a qualified medical professional, such as a physician, physical therapist, physiotherapist, athletic trainer or chiropractor, can identify impairments that may be contributing to the pain. Because parts of the body are so interdependent, the root cause of pain is often caused by something seemingly unrelated, such as pain in the calves while running caused by a weakness in the hips. The focus of the SFMA is on the quality of the execution of each movement, which will then inform the patient’s treatment plan. Remember, the SFMA is for individuals who are already experiencing pain, so the goal of this assessment is to determine the best course of action to get the athlete healthy and moving properly again.

Functional Assessments in Action

Using functional assessments, the physical therapist or athletic trainer will score athletes on how well they perform a number of specific movements and their execution as a whole. We can then take into consideration the information garnered from the test, i.e., any identified asymmetries or weaknesses, and the athlete’s relative score for future activity. For example, a physical therapist would use the results of the initial test as a baseline during rehabilitation following an injury to determine when the player can return to the field. Or, an athletic trainer may use it to retrain an athlete whose body is asymmetrical and make any necessary adjustments to decrease the potential risk of injury. This testing also provides a baseline score of regular physical function, which can be used to monitor progress of strength and mobility as the athlete continues physical training. The information is extremely valuable whether the athlete is currently healthy or experiencing musculoskeletal pain.

It’s important to note that a low score does not necessarily indicate that an injury is on the horizon or that the athlete will never recover, though my colleagues and I have seen a correlation between injuries and test results with athletes. Often when an athlete’s performance earns a lower score, we can make the necessary adjustments and drastically reduce the risk of injury altogether. From my professional experience, athletes tend to take these results as a wake-up call highlighting the need for a dramatic change, particularly if the score of the assessment is extremely low.

There are other assessments that can be used in conjunction with the FMS and SFMA. For example, I use the single leg hop test and the tuck jump assessment when a lower extremity injury has already occurred, or to determine if an athlete is at risk of an injury occurring in the future. The single leg hop test is used primarily after an ACL tear, but may also be used for ankle or knee injuries. To execute the single leg hop test, the athlete puts all of his or her weight on one leg and then explodes in a forward jump and lands firmly on that leg. Then repeats with the alternate leg. The distance between the non-effected leg and the effected leg should be around 90%. If this is not the case, or if the athlete is unable to balance on that leg after the hop, we know that we need to work on motor power. This test is quite telling. In fact, one noted study² found that when performed 6 months after an ACL reconstruction, this test can indicate the athlete’s likelihood of experiencing a successful outcome at one year post-surgery.

The tuck jump assessment has two variations and is most often used to determine if an athlete is at risk of an ACL injury. In the first variation, the athlete is asked to do a single tuck jump—squat, jump, bring both knees to chest, and land. The physical therapist or athletic trainer analyzes the patient’s takeoff, landing, and body position in the air to determine if there is symmetry between the left and right sides. The other variation is a timed test—the athlete performs 10 tuck jumps in a row and is assessed on their form and frequency. If there is a significant pause between jumps or if the foot placement changes between jumps, an imbalance may need to be addressed. A physical therapist can then work with the athlete to retrain the muscles in segments and teach the body to perform the motions appropriately. For example, you may want to break down the components of the tuck jump, first focusing on mastering the squat before moving on to the jumping portion. To figure out what muscles may not be firing properly, I will often change the environment that the movement is being done in by adding in a level of instability or changing the plane of motion.

Limitations and Conclusions

There are many common misconceptions about the FMS and the SFMA, and the role each test can and should play in athletes’ lives. As discussed, these screening and diagnostic tests have specific strengths related to lower extremity injuries, which, when used appropriately, are helpful for baseline testing and injury prevention in athletes. However, the tools themselves are not intended to serve as a stand-alone solution for avoiding injury, an alternative for a medical diagnosis, or a direct performance metric.

We recommend that athletes of all performance levels see a qualified sports medicine clinician for a full assessment and a strategic combination of professional knowledge and outcomes tools to best assess lower extremity strength and stability. While there will never be one direct answer to injury prevention, working with a qualified healthcare professional is the best route to avoiding injury, staying healthy, and becoming a better athlete.

Sami Ahmed, DPT, CES, SFMA, CMTPT is a physical therapist with The Centers for Advanced Orthopaedics, specializing in athletic performance.