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Biomedical subjects

David G Greathouse

Publications and source records attributed to David G Greathouse.

6 recordsLinked to original sources

Median and ulnar neuropathies in university guitarists.

STUDY DESIGN: Descriptive study. OBJECTIVES: To determine the presence of median and ulnar neuropathies in both upper extremities of university guitarists. BACKGROUND: Peripheral nerve entrapment syndromes of the upper extremities are well documented in musicians. Guitarists and plucked-string musicians are at risk for entrapment neuropathies in the upper extremities and are prone to mild neurologic deficits. METHODS AND MEASURES: Twenty-four volunteer male and female guitarists (age range, 18-26 years) were recruited from the Belmont University School of Music and the Vanderbilt University Blair School of Music. Individuals were excluded if they were pregnant or had a history of recent upper extremity or neck injury. Subjects completed a history form, were interviewed, and underwent a physical examination. Nerve conduction status of the median and ulnar nerves of both upper extremities was obtained by performing motor, sensory, and F-wave (central) nerve conduction studies. Descriptive statistics of the nerve conduction study variables were computed using Microsoft Excel. RESULTS: Six subjects had positive findings on provocative testing of the median and ulnar nerves. Otherwise, these guitarists had normal upper extremity neural and musculoskeletal function based on the history and physical examinations. When comparing the subjects' nerve conduction study values with a chart of normal nerve conduction studies values, 2 subjects had prolonged distal motor latencies (DMLs) of the left median nerve of 4.3 and 4.7 milliseconds (normal, < 4.2 milliseconds). Prolonged DMLs are compatible with median neuropathy at or distal to the wrist. Otherwise, all electrophysiological variables were within normal limits for motor, sensory, and F-wave (central) values. However, comparison studies of median and ulnar motor latencies in the same hand demonstrated prolonged differences of greater than 1.0 milliseconds that affected the median nerve in 2 additional subjects, and identified contralateral limb involvement in a subject with a prolonged distal latency. The other 20 subjects demonstrated normal comparison studies of the median and ulnar nerves in both upper extremities. CONCLUSIONS: In this descriptive study of a population of 24 university guitarists, 4 musicians (17%) were found to have electrophysiologic evidence of median neuropathy at or distal to the wrist or carpal tunnel syndrome. Ulnar nerve electrophysiological function was within normal limits for all subjects examined.

Adolescent↗

Effect of fluidotherapy on superficial radial nerve conduction and skin temperature.

STUDY DESIGN: Cross-sectional study. OBJECTIVES: The purpose of this study was to examine the effects of the superficial heating modality, Fluidotherapy, on skin temperature and on sensory nerve action potential (SNAP) conduction latency and amplitude of the superficial radial nerve in healthy individuals. BACKGROUND: Fluidotherapy is a dry, superficial heating modality, which also provides tactile stimulation through the bombardment of air-fluidized cellulose particles. Previous literature has documented a direct relationship between skin temperature and neural conduction velocity; however, there is an absence of published research examining the effects of Fluidotherapy, and of tactile stimulation specifically, on neural conduction. METHODS AND MEASURES: Twenty-one subjects between the ages of 22 and 31 years (mean+/-SD, 25.5+/-0.7 years) and without prior history of diabetes, alcoholism, renal or metabolic dysfunction, current pregnancy, or heat sensitivity were invited to participate. Subjects completed an upper quarter screening exam and medical history form prior to participation. One group underwent heat (46.7 degrees C-48.9 degrees C) and tactile stimulation, a second group underwent tactile stimulation alone, while a third served as controls. Dependent variables were assessed at 3 intervals: before the intervention, immediately after the intervention, and 20 minutes after the intervention. All interventions were 20 minutes in length. RESULTS: A mixed 2-way analysis of variance indicated a significant interaction between time of neural conduction velocity assessment and treatment group for the dependent variables of sensory nerve action potential latency (P< .001) and skin temperature (P< .001). Appropriate post hoc tests were performed for simple effect comparisons. An inverse linear relationship existed between skin temperature and latency (r2 = .65; Pearson product coefficient, -.81). CONCLUSIONS: Fluidotherapy treatment, which combines the effects of heat and tactile stimulation, significantly elevated superficial skin temperature, while tactile stimulation alone and no treatment (control group) did not bring about a temperature change. As the superficial skin temperature increased, there was a concomitant decrease in the distal sensory latency of the superficial radial sensory nerve action potential. These results should be an important consideration for the clinician using superficial heating modalities.

Action Potentials↗

Electrophysiologic response recorded in the first dorsal interosseous muscle with stimulation of the tibial and deep fibular nerves.

Foot intrinsic muscle innervation may demonstrate some variability. The first dorsal interosseous muscle (FDI) is innervated by the deep branch of the lateral plantar nerve (LPN) from the main trunk of the tibial nerve. Contribution from the deep fibular nerve (DFN) may also play a role in the supply of the FDI. Thirty healthy adult volunteers were studied to determine the presence and type of response in the FDI with stimulation of the tibial nerve/deep branch of the LPN and DFN. Both nerves were stimulated at the ankle and knee with a surface and needle recording from the FDI. Latency, amplitude, and conduction values were recorded for each nerve. The incidence of DFN supply to the FDI was 16.6% with a mean ankle amplitude of 152 microV. The incidence of tibial nerve/deep branch of the LPN supply to the FDI was 100%, with a mean ankle amplitude of 5.11 mV. The superficial branch of the LPN is most often studied when evaluating for tarsal tunnel syndrome because the standard recording site is the abductor digiti minimi (ADM). Recording from the ADM, however, frequently produces a less than desirable waveform, and the technical challenges encountered with this site make tarsal tunnel syndrome assessment difficult. It is also possible that selective involvement of the deep branch of the LPN may occur, and if so, recording from the FDI may prove valuable.

Action Potentials↗

Practice analysis: defining the clinical practice of primary contact physical therapy.

STUDY DESIGN: Nonexperimental descriptive research design. OBJECTIVE: To describe the frequency of use and perceived level of importance of professional responsibilities, procedures, and knowledge areas by physical therapists practicing in primary contact care settings and to compare these data to similar data from physical therapists practicing in nonprimary contact care settings. BACKGROUND: Physical therapy services have moved toward a primary contact model of practice in response to changes in the health care delivery system. Several studies have reported the effectiveness of primary contact physical therapy. However, a practice analysis has not been performed to define the clinical practice of primary contact physical therapy. METHODS AND MEASURES: A sample of 212 physical therapists practicing as primary contact providers in the military and civilian sectors, and a comparison group of 250 physical therapists not practicing as primary contact providers were surveyed. A Delphi technique was used to develop the survey instrument, which was pretested by a pilot group. The final survey instrument consisted of 171 items. Chi-square and Kruskal-Wallis tests were conducted to examine significant differences among the 3 groups (P<.001). RESULTS: Of the 212 surveys mailed to the primary contact group, 119 (56.1%) responses were received (82 military physical therapists and 37 civilian physical therapists). Of the 250 surveys mailed to the comparison group, 103 (41.2%) responses were received. There were numerous significant differences among the 3 groups in professional responsibilities, procedures, and knowledge areas, most notably in the areas of selecting and ordering of imaging procedures, identifying signs and symptoms of nonmusculoskeletal conditions, establishing physical therapy diagnoses, and prescribing over-the-counter medications. CONCLUSION: The study describes the clinical practice of physical therapists functioning in the role of primary contact providers or as members of a diverse team of health care professionals in primary care, which may provide curricular direction to professional, postprofessional, and clinical residency or fellowship-based educational settings.

Adult↗