Biomedical subjects

Edward F Owens

Publications and source records attributed to Edward F Owens.

3 recordsLinked to original sources

PubMed2006

Head repositioning errors in normal student volunteers: a possible tool to assess the neck's neuromuscular system.

BACKGROUND: A challenge for practitioners using spinal manipulation is identifying when an intervention is required. It has been recognized that joint pain can interfere with the ability to position body parts accurately and that the recent history of muscle contraction can play a part in that interference. In this study, we tested whether repositioning errors could be induced in a normal population by contraction or shortening of the neck muscles. METHODS: In the experimental protocol, volunteers free of neck problems first found a comfortable neutral head posture with eyes closed. They deconditioned their cervical muscles by moving their heads 5 times in either flexion/extension or lateral flexion and then attempted to return to the same starting position. Two conditioning sequences were interspersed within the task: hold the head in an extended or laterally flexed position for 10 seconds; or hold a 70% maximum voluntary contraction in the same position for 10 seconds. A computer-interfaced electrogoniometer was used to measure head position while a force transducer coupled to an auditory alarm signaled the force of isometric contraction. The difference between the initial and final head orientation was calculated in 3 orthogonal planes. Analysis of variance (1-way ANOVA) with a blocking factor (participants) was used to detect differences in proprioceptive error among the conditioning sequences while controlling for variation between participants. RESULTS: Forty-eight chiropractic students participated: 36 males and 12 females, aged 28.2 +/- 4.8 yrs. During the neck extension test, actively contracting the posterior neck muscles evoked an undershoot of the target position by 2.1 degrees (p <0.001). No differences in repositioning were found during the lateral flexion test. CONCLUSION: The results suggest that the recent history of cervical paraspinal muscle contraction can influence head repositioning in flexion/extension. To our knowledge this is the first time that muscle mechanical history has been shown to influence proprioceptive accuracy in the necks of humans. This finding may be used to elucidate the mechanism behind repositioning errors seen in people with neck pain and could guide development of a clinical test for involvement of paraspinal muscles in cervical pain and dysfunction.

Journal Article↗

PubMed2004

Stability of paraspinal thermal patterns during acclimation.

BACKGROUND: Paraspinal thermography has been used by chiropractors since 1924. One method of its interpretation is with the use of "pattern analysis"-a method that assesses temperature differentials (patterns). This, in turn, theoretically provides information about nervous system function. When a warm back is exposed to the cooler air in the examining room, the skin temperature, in general, drops but the differentials could remain fairly constant. OBJECTIVE: To determine what changes occur in paraspinal heat patterns when the back is exposed to room temperature. STUDY DESIGN: Observational; measures repeated at 5-minute intervals for 31 minutes. METHODS: Thirty subjects were scanned with digital infrared thermographic instrumentation every 5 minutes over a 31-minute period for a total of 7 readings. A computerized calculation of percent similarity between consecutive comparisons of the readings was then performed to determine if and when the pattern stabilized. RESULTS: Cervical spine temperatures remained constant while lower back temperatures, in general, decreased for the entire 31-minute recording period. Although the results varied among subjects, on the average, the patterns stabilized after 16 minutes. CONCLUSIONS: Once the patient's back is exposed to cooler room temperature, the skin temperature decreases constantly for 31 minutes; however, the pattern becomes stable after 16 minutes. Readings taken for the purpose of pattern analysis during this 16-minute period may be unreliable for some patients. Therefore, a 16-minute acclimation period is recommended. Further research is needed to not only verify this finding with the same equipment in a separate experiment but to verify it as well with other types of temperature instrumentation.

Acclimatization↗

PubMedDate not supplied

Paraspinal skin temperature patterns: an interexaminer and intraexaminer reliability study.

BACKGROUND: Paraspinal thermography is used by chiropractors as an aid in assessing the presence of vertebral subluxation. Few reliability studies have been carried out, with mixed results. Digital infrared scanning equipment is now available with location tracking that may enhance reproducibility. Digitized scans enable a computer-aided interpretation of thermographic patterns. OBJECTIVE: To assess the ability of examiners to reproduce thermal patterns. STUDY DESIGN: Repeated measures with 2 examiners assessing the same patient on 2 occasions. Thirty asymptomatic students served as subjects. METHODS: A TyTron C-3000 handheld thermographic scanner interfaced to a Microsoft Windows compatible personal computer was used for all recordings. Each examiner recorded 2 scans on each patient. It took an average of 3 minutes to complete all 4 scans. Data were exported to a spreadsheet for initial analysis, then SPSS was used for calculation of intraclass correlation coefficients (ICC). Since the starting and stopping points of scans were not always the same, care was taken to align scans visually, using well-distinguished peaks on the charts as guides. Scans were cropped to remove artifacts that might have occurred at the beginning and end of the scans. Intraexaminer and interexaminer ICCs were calculated. RESULTS: Skin temperatures ranged from 35.4 degrees C to 30.0 degrees C over all scans. The average temperatures changed little from the first to the last scans, indicating that subjects' overall skin temperatures were stable during the scanning procedure. Intraexaminer ICCs ranged from 0.953 to 0.984. The left and right channel data show slightly higher congruence than the Delta channel. The interexaminer reliability coefficients ranged from 0.918 to 0.975. Again, the Delta channel shows slightly less reliability, although the ICCs were quite high for all channels. CONCLUSION: Intraexaminer and interexaminer reliability of paraspinal thermal scans using the TyTron C-3000 were found to be very high, with ICC values between 0.91 and 0.98. Changes seen in thermal scans when properly done are most likely due to actual physiological changes rather than equipment error.

Adult↗