Summary and Perspective of Recent Literature
Maccio JR, et al. (2017). Directional preference of the wrist: a preliminary investigation. Journal of Manual & Manipulative Therapy; Doi: 10.1080/10669817.2017.1283767.
The objective of this investigation was to apply Mechanical Diagnosis and Therapy (MDT) to patients with wrist disorders and to determine the appropriate classification: Derangement, Dysfunction, Postural or OTHER. This study was in a case report style and took place in a private certified McKenzie spine and extremity out-patient clinic. The primary author has a doctorate in physical therapy and a Diploma in MDT. In addition, four students who were trained by the lead author, were co-examiners and their treatment was overseen by the lead author.
Nineteen patients with ages ranging from 15 to 69 years old were evaluated following MDT principles. Fifteen of these were classified as having a Wrist Derangements, two as Cervical Derangement and two as OTHER.
The patients classified with Wrist Derangement were evaluated to determine directional preference and were placed into one of four categories for the purposes of the study. The first, ‘mechanical stress’ indicates a repeated or sustained movement that is used most often throughout the day. ‘Directional vulnerability’ was a term used to describe the movement that reproduces the patient’s symptoms. Painful Movement is the most painful movement as indicated by the patient’s pain rating via the Numerical Pain Rating Scale. Finally, ‘obstructed movement’ was defined as the direction that is most limited compared with the opposite wrist.
Directional Preference was found for 15 of the patients and so they were classified with Wrist Derangements. Five of these patients required a change in direction following re-evaluation to promote continued resolution.
Four of these patients also required traction with the Directional Preference exercise and two needed some specifically focused overpressure.
These patients were seen for a total of three to six visits to ensure proper management of symptoms prior to discharge. The other 10 patients were all able to manage their symptoms with the initial motion in their directional preference and they were all discharged at their second follow-up visit.
Investigators found 73.3% (11/15) of the patients demonstrated Directional Preference in the direction opposite of their ‘mechanical stress’, where 66% (10/15) had Directional Preference opposite of ‘directional vulnerability’. Fifty three percent of the patients found Directional Preference associated with their most ‘painful movement’ (8/15). Finally, 46% of the patients found Directional Preference in the direction of the ‘obstructed movement’ (7/15).
This study found a high number of patients classified with a Wrist Derangement, however unlike previous studies, they found that patients required movement in multiple directions with various loading strategies to achieve directional preference (79%). These included loaded wrist extension or flexion, unloaded wrist flexion, wrist flexion with manual traction, wrist supination with proximal anterior and distal posterior over-pressure and unloaded supination with high velocity whip. Previous studies focused on wrist extension and ulnar deviation as the only two motions to achieve directional preference.
In conclusion, patients included in this case series had a high success rate with MDT intervention. Wrist Derangement Syndrome was common and many of the patients were only seen for two visits with successful long-term management at home. MDT has been studied extensively in the spine, however this study adds to the growing knowledge base in the extremities. The study has also uniquely given some insight into the relationship between certain variables and directional preference. This encourages clinicians to use information gathered from a detailed history in order to guide the examination process and to formulate hypothesis as to cause and effect.
This study supports previous extremity studies indicating that MDT clinicians can use the MDT classifications of Derangement, Dysfunction and Postural Syndrome and OTHER subgroups and effectively apply them to the wrist. It is also important to note that two of the original 19 patients who were evaluated for wrist pain were categorized as having a Cervical Derangement. This also supports the recommendation to screen the cervical spine thoroughly for all upper extremity presentations, even down to the wrist.