How do I know when my ACL rehab is over and I’m ready to return to sport?
Lower limb asymmetry testing is an essential part of the return-to-sport assessment after an injury. It helps determine if there are significant imbalances in strength, flexibility, or movement patterns between the injured and uninjured limbs. Here's a general outline of how to conduct lower limb asymmetry testing on your own and with a licensed Physical Therapist:
Tests That Can Be Done On Your Own:
Absolute strength testing:
I recommend picking a 2-3 rep maximum on an exercise that can be done single leg while protecting the leg and graft. Single rep max can put you at risk for re-injury if you haven’t worked up to that intensity prior to testing. Suggested exercises include a lunge, Bulgarian squat, or leg press.
Surgical side should be able to perform a minimum of 90% of the non-surgical side.
Strength endurance testing: measure an individual's ability to sustain or repeatedly exert force over an extended period of time.
Example exercises:
Single-leg wall Sit Test: In this test, a person holds a seated position against a wall for as long as possible, which measures lower body endurance and strength
Step Test: Step up and down on a bench or platform at a specific rhythm for a set duration (ex: 1 min) to assess single leg muscular endurance and see how many reps you can get within the set time
Surgical side should be able to perform a minimum of 90% of the non-surgical side.
Single leg hop testing: measures lower limb power, balance, and neuromuscular control
Jump forward as far as you can on a single leg and measure the distance.
Surgical side should be able to perform a minimum of 90% of the non-surgical side.
Confidence Assessment Testing: Assessing an athlete’s psychological readiness and subjective confidence plays a significant role in an athlete’s ability to perform at their best and to reduce the risk of re-injury.
Self-perceived confidence and perceived risk of re-injury can be determined by taking a questionnaire like the Knee injury and Osteoarthritis Outcome Score
Tests That Should Be Done With Your Physical Therapist:
Specific Battery Testing Protocols: A series of tests that are done together, usually in the same session, and are pooled to gather a combined score of asymmetry.
Isokinetic Strength Testing: Measure the strength of the quadriceps and hamstrings, comparing the injured and uninjured limbs. This helps identify any significant strength imbalances.
Single-Leg Hop Tests: Tests like the single-leg hop for distance, triple hop, and crossover hop are commonly used to assess limb symmetry, power, and neuromuscular control. Compare the performance of the injured limb to the uninjured limb.
Triple Hop for Distance: This test measures single-leg power, stability, and coordination. It provides valuable information on the ability to absorb and generate force on the injured leg.
Crossover Hop for Distance: Similar to the triple hop, this test assesses the athlete’s ability to control and generate power on the injured limb during a lateral movement.
Force plate symmetry testing for peak force development and landing impact. The magnitude and symmetry of the peak vertical ground reaction force (pVGRF) are collected and analyzed with single-leg jumps on force plates.
Y-Balance Test (YBT): The YBT evaluates dynamic balance, strength, and flexibility. It involves reaching in different directions while standing on one leg. A decrease in performance on the injured side can indicate deficits.
Functional Movement Screening (FMS): Should be conducted by a certified professional that has training in how to score this test. The FMS detects movement pattern dysfunctions and imbalances.
Range of Motion Assessment: Measure the range of motion in both limbs, looking for any significant differences.
Gait Analysis: Analyze the patient's gait to identify any abnormalities or compensations in their walking or running pattern.
Limb Symmetry Index (LSI) Calculation: Calculate a symmetry index by comparing the results of the injured limb to the uninjured limb. The research is suspect and highly circumstantial, but a general rule of thumb is to aim for an LSI of 90% or higher before considering an athlete ready to return to their sport.
It's important to work with a qualified sports medicine or physical therapy professional who can conduct these assessments and guide the rehabilitation process effectively. The specific tests and protocols may vary depending on the type of injury and the sport in question.
