Sports Medicine Research: In the Lab & In the Field: Cool It Down Before You Work It Out (Sports Med Res)


Wednesday, November 5, 2014

Cool It Down Before You Work It Out

Quadriceps muscle function after rehabilitation with cryotherapy in patients with anterior cruciate ligament reconstruction.

Hart JM, Kuenze CM, Diduch DR and Ingersoll CD. J Athl Training. [Epub Ahead of Print].

Take Home Message: Among knees with a history of anterior cruciate ligament (ACL) reconstruction and chronic quadriceps dysfunction, the application of cryotherapy prior to performing exercises may help mitigate arthrogenic muscle inhibition and improve muscle function.

Following ACL reconstruction, patients often suffer from persistent quadriceps weakness potentially caused by arthrogenic muscle inhibition. If clinicians could reduce arthrogenic muscle inhibition then patients may be able to increase quadriceps strength.  Therefore, Hart and colleagues compared quadriceps muscle function in patients treated with cryotherapy, exercise, or both. The authors included 30 participants who had undergone ACL reconstruction at least 6 months prior to the study, and were cleared for physical activity by their physician. At baseline, the authors measured the patients’ quadriceps activation and quadriceps Hoffmann reflex. To assess quadriceps activation, patients sat and performed 2 to 3 maximum voluntary isometric contractions of the quadriceps. As their torque reached plateau, the researchers applied an electrical stimulus to increase torque above the maximum voluntary isometric contraction value. The central activation ratio was defined as the torque generated by a maximum voluntary isometric contraction divided by the electrically stimulated activation. The authors measured Quadriceps Hoffmann reflex by applying a short electrical stimuli to the patient’s femoral nerves (electrode placed in the inguinal fold) in a supine position. After baseline testing, researchers randomized the participants into 1 of 3 treatment groups for a 2-week intervention. Participants in the cryotherapy group applied 2 ice bags to the anterior and posterior sides of the knee for 20 minutes everyday. Participants in the exercise group, performed a 1-hour long, progressive exercise program daily. Participants randomized to the combination group performed cryotherapy for 20 minutes followed by the same exercise program as performed by the exercise group. All participants attended four supervised treatment sessions during the 2-week period. Patients’ quadriceps activation and Hoffmann reflex were measured following the 2-week intervention. Overall there were no significant differences between any of the treatment groups for any variables. However, there was trends indicating that participants who received both cryotherapy and exercise increased knee extension torque while participants in the cryotherapy group or exercise group did not.

Overall, the current study provides preliminary support for the use of cryotherapy prior to exercise in patients who have undergone ACL reconstruction and who have chronic quadriceps muscle dysfunction. The results of this study should be particularly interesting to clinicians as it shows how cryotherapy can be beneficial in mitigating arthrogenic muscle inhibition as well as pain. By using cryotherapy prior to the exercises, clinicians could reduce the muscle inhibition during the exercises and maximize the benefits of an exercise program. More research will be needed to determine if cryotherapy prior to exercises is also effective among patients with different injuries as well as varying levels of pre-injury activity, amounts of quadriceps inhibition, times since injury, ages, and delays between surgery and intervention. Until this can be done however, clinicians should use cryotherapy to treat pain and possibly muscle inhibition throughout the rehabilitation process.

Questions for Discussion: Have you used cryotherapy prior to exercise to help improve quadriceps activation? When do you use cryotherapy?

Written by: Kyle Harris
Reviewed by: Jeffrey Driban 

Related Posts:

Hart, J., Kuenze, C., Diduch, D., & Ingersoll, C. (2014). Quadriceps Muscle Function After Rehabilitation With Cryotherapy in Patients With Anterior Cruciate Ligament Reconstruction Journal of Athletic Training DOI: 10.4085/1062-6050-49.3.39


Jennifer Joseph said...

This article really opened my eye to possibly of implementing cryotherapy before rehabilitation in my practice. I would have never thought to use cryotherapy in this manner but based on these results I think its worth a try. I think ideas for future studies would be to implement this on patients who are 3 months post ACL-R and see if their MVIC torque results are different to those 6-months post ACL-R. I also think it would be interesting to follow these patients for a longer intervention period to see if their MVIC torque plateau after a certain number of weeks. I also think more exploration needs to be done to answer why joint position sense is compromised after cryotherapy, but muscle activation is not. Lastly, I think its important to establish an optimal time window for when cryotherapy as a disinhibitor modality is most useful. Lots of opportunities for future research on this topic!

Jeffrey Driban said...

Hi Jennifer, those are all great questions that hopefully will be explored in future research. It sounds like a great line of research. Thanks for the comment.

Landon Lempke said...

This is a very interesting article. The idea of cryotherapy being used before rehabilitation exercises is one that I think most clinicians (myself included until reading this article) generally don't think of because they believe it causes mild ROM restriction, temporary decrease in viscoelastic properties, and poor motor control. Essentially the “old school” method of using ice to only reduce pain and inflammation is what still sticks around, despite research showing discrepancies in this old ideology.
That being said, if more research is done regarding AMI and the positive effects cryotherapy plays (not just at the knee with the ACL, but at all joints), I think we could see future implementation of this process in the future following post ACL surgery. If we can gain full or improved neuromuscular control earlier on in the rehab process, we could potentially see less muscular impairments following ACL surgery.
I hope to see more studies testing this hypothesis.

Kyle said...


Great comment! Thank you! I agree that there are some far-reaching implications here if more research can be completed, especially concerning other joints. I also think your comment about this treatment not being considered because of "old school" methods addresses what we hope SMR can help clinicians address. With a vast array of research being published, we hope to help clinicians stay as abreast as possible because best clinical practice can sometimes contradict this "old school" method. Thanks again for the great comment!

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