Sports Medicine Research: In the Lab & In the Field: Age and Quadriceps Strength Indicators on Noncopers Ability to Pass Return to Sport Criteria (Sports Med Res)


Wednesday, October 24, 2012

Age and Quadriceps Strength Indicators on Noncopers Ability to Pass Return to Sport Criteria

Preoperative Predictors for Noncopers to Pass Return to Sports Criteria After ACL Reconstruction.

Hartigan EH, Zeni J, Di Stasi S, Axe MJ, and Snyder-Mackler L. J Appl Biomech. 2012;28:366-373.

Following anterior cruciate ligament (ACL) rupture, it is often suggested that an athlete may be able to return to sport 6 months post-surgery, regardless if the athlete is a coper (can continue high-level activates without needing an ACL reconstruction) or noncoper (lacks the ability to stabilize and limit instability without reconstruction). This timeframe, however, has never been verified through a prospective study. Therefore, Hartigan and colleagues completed a study to determine which preoperative variables predict the ability of a noncoper to return to sport at 6 months. The study also sought to determine if patients who had strength gains preoperatively would have better outcomes postoperatively. Patients were eligible for inclusion if they were classified as a noncoper (classification completed by a physical therapist), 15-55 years old, either contact or non-contact ACL rupture confirmed by magnetic resonance imaging, 3 mm or greater anterior translation between limbs using a KT-1000 arthrometer, and were within 10 months of injury. A total of 38 patients (11 females, 27 males, mean 28.6 year old) attended 10 preoperative physical therapy sessions. Rehabilitation consisted of isotonic and isokinetic quadriceps strengthening exercises (wall slides, step exercises, etc). Three months following ACL reconstruction and after meeting 4 clinical milestones (knee effusion of grade 1 or less, full knee range of motion, quadriceps strength index of at least 80%, and no pain with hopping while braced) athletes were allowed to attempt to pass return to sport criteria. Return to sport criteria consisted of 90% quadriceps strength symmetry between injured and noninjured limb and a score of 90% on both the KOS-ADLS and global rating scale. Gait analysis was performed in each patient using a three-dimensional, eight-camera motion analysis system and force platform. Quadriceps force measurements were recorded with a maximum, isometric contraction on a dynamometer. Overall, age, quadriceps strength, and knee flexion moments during gait on the involved limb were significantly different between those who passed and failed the return to play criteria. The results demonstrated older patients, patients with weaker quadriceps, and patients with less knee flexion during walking were less likely to pass return to sport criteria. When considering age, quadriceps strength, and knee flexion moments the authors could correctly predict 69% of the patients who passed and 82% of patients who failed to meet the return to sport criteria at 6 months post ACL reconstruction. Improved quadriceps strength after physical therapy was also significantly predictive of return to activity at 6 months.

Overall, these results are important for clinicians to be aware of when determining return to sport rehabilitation and timeframes. Perhaps this data is most useful as a guide to clinicians on what factors to focus on the most, in hopes of returning their athletes to play. While age is not a modifiable factor and debate exists over how modifiable knee flexion moments during gait are, the major focus of preoperative rehabilitation should focus on increasing quadriceps strength. Furthermore, future research should explore how these factors would influence passing or failing return to sport during more sport specific activities (running, cutting, etc.). While age is not modifiable, it is a significant predictor of an athletes’ ability to pass return to sport criteria, and should be something which clinicians discuss with their athletes both pre and post-surgery to develop more appropriate return to sport timelines for the individual athlete. Tell us what you think. What factors do you focus on preoperatively with your ACL reconstruction patients? Do you counsel your patients on unmodifiable factors, such as age, and discuss how that factor may impact the overall recovery timeline?

Written by: Kyle Harris
Reviewed by:  Stephen Thomas

Related Posts:

Hartigan EH, Zeni J Jr, Di Stasi S, Axe MJ, & Snyder-Mackler L (2012). Preoperative Predictors for Noncopers to Pass Return to Sports Criteria After ACL Reconstruction. Journal of Applied Biomechanics, 28 (4), 366-73 PMID: 22983930


BJ Maack said...

Setting reasonable post-op goals/expectations with a patient ahead of surgery is something I try to do. I feel it's important to do so in order to help with the mental aspect of the rehab process. This can actually be harder for some than the physical.

Age is an important thing...I recently rehabbed a 39-40 year old ACL patient and had to set the table with her as she compared herself to a 23 year old patient. Reasonable expectations...

Kate said...

I am an athletic trainer that has only worked with high school to college age athletes so I have not had to have a discussion with my patients regarding how their age will affect their recovery. However, I do largely focus on quadriceps and hamstring strength as well as ROM throughout ACL rehabilitation. At the moment I have a patient who 3 weeks post op ACL reconstruction and still cannot activate his quad or flex his knee past 60 degrees. I am a bit surprised by his results because before his surgery I had him perform quad strengthening and ROM exercises thinking that it may help him after surgery but that does not seem to be the case. After reading this summary I'm beginning to wonder if I need to have a talk with him and extend his expected recovery time. In this article does it state when quad strength and proper ROM had to be seen in a patient to determine if they would pass return to play criteria?

Kyle Harris said...

Kate and BJ,

You both bring experiences to the table that support the notion that all patients should have a RTP timetable specific to them, partially dependent on the patient's age. Kate, specific to your question, the article did address quad strength. The article stated that the younger a patient and the higher the quad strength was, the more likely they were to pass RTP criteria. They did not address ROM, but rather limb motion in this study. Based on your comment though, looking at ROM in combination with quad strength in future research could be very helpful to clinicians.

Nate said...

This area of research is very interesting to me. We know quadriceps strength is important and I think it is a well known focus on early ACL rehabilitation. I don't know how well we are addressing quad strength. We know quad sets, neuromuscular re-education, SLR are the common phase 1 rehab exercises that I have seen being used early on after injury or surgery. We know that these exercises increase strength and decrease arthrogenic muscle inhibition. Going from there I think it becomes more and more important to re-evaluate and address specific deficits as they arise. Research like this shows us that when we re-evaluate we can predict how these athletes will do in the longer term. This will allow us to better educate or athletes on expectations and help use deliver better care overall.

Kyle said...


Great comment. I couldn't agree with you more. The re-evaluation and immediate addressing of deficits is crucial to success of the rehab. I think the thing which has been most helpful with many of my patients is the idea of goal setting. If athletes understand what is expected of them, and why those goals are set (documented better RTP ability), they are more highly motivated to meet those goals because they better understand what is at stake. Again great comment!

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