To the Editor: 

I read the article by Burnham et al¹ in the March issue of The Journal of the American Osteopathic Association with great interest. It is a comprehensive study, and I applaud the authors for their excellent use of objective measures to evaluate the effects of osteopathic manipulative treatment (OMT) on the median nerve and carpal tunnel syndrome. 

However, I am concerned that the authors did not apply the optimal OMT techniques to the carpal tunnel, as noted in my 2005 study² and again in a study I coauthored in 2014.³ These articles clearly describe that one can achieve the maximum effect for elongating the transverse carpal ligament (TCL) by using the transverse extension and guy-wire manipulative techniques.^2,3 Burnham et al¹ focused more on the opponens roll maneuver and “high-amplitude springing” of the carpal bones. It is essential to apply vigorous manipulative release of the TCL at the distal carpal bone level (trapezium-hamate), and the results can be documented by palpatory assessment after treatment, as noted by my 1994 study⁴ when using a Likert-type rating scale of 0 to 5 (0=no restriction, 5=extremely marked restriction), with the critical level of restriction graded at 2/5. It was instructive that patients improved when the restriction decreased below a 2/5 level— once this threshold was reached, it could be used to motivate patients to continue treatment.⁴ Burnham et al¹ did reassess patients with “tissue texture changes” and “restored range of motion,” but these measures are less specific than a quantitative determination of palpatory restriction. 

In addition, my 2005 study² clarified that the optimal approach to managing carpal tunnel syndrome is to combine manipulation with self-stretching. I objectively documented that the maximum TCL lengthening occurred when stretching followed manipulative “priming” of the TCL.² This laboratory finding mimics the optimal clinical situation where the patient obtains manipulation from the physician in the office and is provided stretching instruction to perform independently.² Stretching exercise complements the manipulation, “building on the manipulative efforts” by making the TCL more responsive to the subsequent stretching, but the patients must be instructed in precise techniques to be performed several times daily.^2,3 

I agree with the authors¹ when they acknowledge that objective measures taken after the final manipulation may have been too early to determine maximum changes in the electrophysiology and morphology of the median nerves,¹ because such changes often lag several weeks behind clinical improvement.⁴ This limitation of the study’s conclusions is clinically significant, and I believe the authors should have repeated measurements 4 to 6 weeks after the final OMT session.