Conducting A Quick And Easy Functional Lower Extremity Exam Of An Athlete
In the functional tests, we are looking for three things: symmetry, mobility and stability. As we often do with other exam techniques, we start looking very generally at the overall picture and then gradually focus our exam based on our findings and the patient’s chief complaint.
Functional movements require a strong and balanced core. It is well documented that weakness of the muscles of the low back, pelvis and proximal femur are a significant causative factor in spine, hip and patellofemoral injuries.1 There is also evidence that improved core strength affects rearfoot eversion and rearfoot eversion velocity.2
Testing core strength endurance is also important because many athletes may demonstrate adequate core strength in clinic but develop weakness or imbalances as they fatigue during activity. It is often surprising to find that even highly trained athletes can demonstrate core weakness.
A Guide To Tests For Core Stability
Single leg squat test. The patient stands with his or her hands on the hips or at the sides, transfers weight to one leg, extends the knee of the non-weightbearing leg with the non-weightbearing foot anterior to the body and bends the weightbearing knee until the knee is over the forefoot. The patient holds the position for 10 seconds while the non-weightbearing foot remains off the floor. The patient does this test with both legs.
Look for a smooth, coordinated movement, stable balance, level hips and shoulders, and the patella tracking over the second metatarsophalangeal joint. Obvious signs of deficits include: poor coordination of movement, flailing arms, shoulder and/or hip drop, a forward leaning torso and a medially deviating knee.2,3
Planks. In the first position, the patient lies prone on the exam table or floor, and then raises his or her body to support weight with only toes, elbows and forearms. In the second position, the patient lies on the side and then raises the body to support his or her weight with only the lateral aspect of the bottom foot and the elbow. Test the side plank on both the left and the right. The patient should be able to hold each position for a minimum of 30 seconds.4
Look for proper alignment of the body from the feet through the cervical spine as well as a stable hold of the test with minimal shaking. Obvious signs of deficits include: complete inability to perform the action, tendencies to elevate or drop the pelvic area from the proper alignment and rotational inequalities in the pelvis.
Physical therapist Jay Dicharry often says “The test becomes the exercise” in instances when athletes demonstrate poor function.5 For example, athletes with poor core endurance would do plank exercises as part of their therapy.
How To Evaluate Balance And Proprioception
It goes without saying that balance is important in any weightbearing activity but as with core strength, there are a surprisingly significant number of our patients who will demonstrate significant deficits. Balance and proprioception issues increase the risks of ankle sprains.6 Fatigue and chronic ankle instability disrupt not just foot and ankle function, but also the dynamic postural control of the entire limb.7 In 2004, Malliou and colleagues found that proprioception training improved balance and reduced not just ankle sprains but overall injury rates in soccer players.8
Single leg balance test. Balance is of course important to all movement. Research has shown poor balance to increase the risk of injury to basketball players and proprioception training improves balance and reduces injury rates in young soccer players.6,8