Mary P. Dimick

Sensibility testing in peripheral-nerve compression syndromes. An experimental study in humans.

Sensibility testing in peripheral-nerve compression syndromes was investigated in an experimental study in humans. Twelve volunteer subjects had controlled external compression of the median nerve at the carpal tunnel at a level of forty, fifty, sixty, and seventy millimeters of mercury. The subjects were then monitored for thirty to 240 minutes with four sensory tests: two-point discrimination, moving two-point discrimination, Semmes-Weinstein pressure monofilaments, and vibration. Sensory and motor conduction, subjective sensations, and motor strength were also continuously tested. The threshold tests (vibration and Semmes-Weinstein monofilaments testing) consistently reflected gradual decreases in nerve function in both subjective sensation and electrical testing, while the innervation density tests (two-point discrimination and moving two-point discrimination) remained normal until nearly all sensory conduction had ceased. Decreased muscle strength occurred late, and not until changes had already occurred in each of the sensory tests. Threshold tests of sensibility correlated accurately with symptoms of nerve compression and electrodiagnostic studies, and are being evaluated for clinical use in a variety of peripheral-nerve compression syndromes.

Results of treatment of severe carpal-tunnel syndrome without internal neurolysis of the median nerve.

Thirty-three hands (twenty-nine patients) had a release of the carpal tunnel without internal neurolysis for severe carpal-tunnel syndrome. All of the hands had increased values for two-point discrimination or thenar atrophy, or both. Twenty-three (89 per cent) of the twenty-six hands that had increased values for two-point discrimination and twenty-six (87 per cent) of the thirty hands that had an elevated result on Semmes-Weinstein testing had normal values at follow-up. Nine (90 per cent) of the ten hands that had weakness of the thenar muscles (grade-3 strength or less) regained grade-4 or 5 strength. Thirteen (65 per cent) of the twenty hands that had thenar atrophy regained normal muscle bulk. Eighteen (62 per cent) of the twenty-nine patients had complete resolution of symptoms and signs of compression of the median nerve. No significant difference was found between the results in this series of patients and those in a previously reported similar group of patients who were treated by release of the carpal tunnel combined with internal neurolysis of the median nerve.

Sensibility testing in patients with carpal tunnel syndrome.

We evaluated the sensibility of the hand preoperatively and at intervals postoperatively in twenty-three hands of twenty patients with idiopathic carpal-tunnel syndrome who underwent carpal tunnel release. Tests of sensibility included the threshold tests (vibrometry, 256-cycles-per-second vibration, and Semmes-Weinstein monofilaments) and one innervation-density test (two-point discrimination). In addition the wrist-flexion test, nerve-percussion test, and tourniquet test were performed preoperatively. Only five of the twenty-three hands had abnormal two-point discrimination and each of these also had markedly abnormal threshold-test values. Nineteen of twenty-three hands preoperatively had decreased sensibility detected by both Semmes-Weinstein monofilament testing and vibrometry. Six weeks after carpal tunnel release, all of the hands demonstrated improvement on threshold testing, and 65 per cent had normal values.

Forearm arterial injuries

The effects of single forearm arterial injuries with and without associated neurological injuries were studied. Fifty subjects were evaluated: seven patients with isolated arterial lacerations, 15 patients with isolated nerve lacerations, 13 patients with combined nerve and arterial injuries, and 15 control subjects. A series of noninvasive peripheral vascular studies were correlated with the symptoms produced by a controlled cold-environment exposure. The hemodynamic alterations associated with symptoms of hand ischemia, and particularly with cold intolerance, were studied. Unrepaired single arterial injuries caused modest, consistent alterations in hand vascularity, but few signs of ischemia or symptoms of cold intolerance. The remaining intact artery demonstrated a consistent increase in flow velocity. Combined nerve and artery injuries caused the most significant alterations in hand vascularity, and median nerve and associated artery injuries caused the most disabling symptoms. Single arterial lacerations had no effect on the rate or completeness of recovery from associated nerve injuries.

Vibratory sensory testing in acute peripheral nerve compression

Vibratory thresholds were continually measured with a variable-amplitude vibrometer during periods of controlled median nerve compression in 12 human volunteers. Tissue fluid pressure in the carpal canal was maintained at 50 mm Hg, a level which caused a complete loss of nerve function in all subjects by 45 minutes. In all subjects vibratory thresholds proved to be the earliest test indicating a decrease in nerve function. Semmes-Weinstein pressure testing and 256 cycles/sec vibratory sensibility correlated well with measurements of vibratory thresholds and with the electrodiagnostic testing. Static and moving two-point discrimination did not become abnormal until late in the clinical testing. The vibrometer has significant potential as a clinical and research instrument in nerve compression syndromes. This study supports the use of vibratory stimuli as a noninvasive diagnostic test; it is currently undergoing evaluation in a number of clinical studies.

A new practice analysis of hand therapy

The Hand Therapy Certification Commission, Inc. (HTCC) conducted a role delineation in 2001 to characterize current practice in the profession of hand therapy. Building upon previous HTCC studies of practice (i.e., Chai, Dimick & Kasch, 1987; Roth, Dimick, Kasch, Fullenwider & Taylor, 1996), subject matter experts identified the clinical behaviors, knowledge, and technical skills needed by hand therapists. A large scale survey was conducted with therapists across the United States and Canada who rated the clinical behaviors, knowledge, and technical skills in terms of their relevance to practice, and provided information about their own patient populations. A high survey return rate (72%) was indicative of the professional commitment of CHTs to their profession. Results of the survey are discussed and practice trends are identified. A new test outline for the Hand Therapy Certification Examination was created based on the results of the survey, and the 1987 Definition and Scope of Hand Therapy was revised.

2008 Practice Analysis Study of Hand Therapy

In 2008, the Hand Therapy Certification Commission (HTCC), in consultation with Professional Examination Service, performed a practice analysis study of hand therapy, the fourth in a series of similar studies performed by HTCC over a 23-year period. An updated profile of the domains, tasks, knowledge, and techniques and tools used in hand therapy practice was developed by subject-matter experts representing a broad range of experiences and perspectives. A large-scale online survey of hand therapists from the United States, Canada, Australia, and New Zealand overwhelmingly validated this profile. Additionally, trends in hand therapy practice and education were explored and compared with the previous studies. The results led to the revision of the test specifications for the Hand Therapy Certification Examination; permitted refinement of the definition and scope of hand therapy; identified professional development and continuing education opportunities; and guided HTCC policy decisions regarding exam and recertification eligibility requirements.

A Role Delineation Study of Hand Therapy

Abstract In 1985 the American Society of Hand Therapists (ASHT) conducted a role delineation study (occupational analysis) of hand therapy. ASHT distributed a questionnaire to 1046 therapists, 49% of whom responded. The respondents provided information about themselves and their practices; rated a variety of professional activities and concepts on frequency of occurrence and degree of importance in practice; stated where they had learned these activities and concepts as well as where they thought they should be learned; and expressed opinions about issues related to the certification of hand therapists. The study revealed a core set of important and frequently performed activities. The data from this occupational analysis can serve to define the practice of hand therapy, to identify educational objectives, to provide data for further research into the characteristics of the profession, and to establish the basis for a formal process of certification in hand therapy.

Practice analysis of hand therapy.

In 1994, a practice analysis (role delineation study) was conducted on the profession of hand therapy. This study was conducted as a follow-up to the original study conducted by the American Society of Hand Therapists (ASHT) in 1985. A representative group of content experts developed a description of hand-therapy practice, and this description was validated using a questionnaire. The questionnaire was distributed to a random sample of 400 certified hand therapists (CHTs), of whom 50% responded. The respondents provided confirmation of the accuracy of the description of hand therapy. The survey results were used to update the test specifications for the Hand Therapy Certification Examination. The results enabled the Hand Therapy Certification Commission to improve upon its certification program by clarifying and expanding the definition of hand therapy. The 1994 findings were also compared with the results of the 1985 study.

Thirty years of hand therapy: The 2014 practice analysis

STUDY DESIGN Quantitative and descriptive study. INTRODUCTION In 2014, the Hand Therapy Certification Commission (HTCC), in consultation with Professional Examination Service, performed a practice analysis study of hand therapy, the fifth in a series of similar studies performed by HTCC over a 30-year period. PURPOSE The purpose of the study was to gather data on current hand therapy practice to ensure the content of the Certified Hand Therapist (CHT) examination and credentialing program requirements match current practice. METHODS Subject-matter experts from the United States and Canada, representing a broad range of experiences and perspectives, developed an updated delineation of the domains, tasks, knowledge, and techniques and tools used in hand therapy practice. Practicing hand therapists from the United States, Canada, Australia, and 13 other countries reviewed the delineation in a large-scale online survey. RESULTS The survey overwhelmingly validated the updated profile. Additionally, the survey explored trends in hand therapy practice and compared findings with previous studies. The results were analyzed and compared with findings from previous studies. CONCLUSION This analysis led to the revision of the test specifications for the HTCC; the affirmation of the definition of hand therapy; the refinement of the scope of hand therapy practice; and guidance for HTCC policy decisions. LEVEL OF EVIDENCE Not applicable.