M.Tech. (Chiropractic) / Aim: The aim of this study was to determine if a chiropractic adjustment had an effect on muscle strength. The study then aimed to compare the effects a resistance training protocol, to a chiropractic adjustment, to a combination of these two treatments on the neck strength of individuals with cervical facet syndrome. Method: This study consisted of three groups of 10 participants each. The participants were grouped by stratified sampling to balance the groups in terms of age and gender. The participants ranged in age from 22 to 28 years. There were 18 male and 12 female participants. Participants were examined and accepted into the trail according to inclusion and exclusion criteria. Treatment was allocated according to groupings. Group 1 received a resistance training protocol, group 2 received chiropractic adjustment only and group 3 received a combination of both treatments. Procedure: Treatment consisted of 6 treatment sessions and a 7th follow up session, over a three week period. Participants in group 1 and 3 were instructed to perform the demonstrated resistance training protocol 3 times a week for 3 weeks. Participants in group 2 and 3 received chiropractic adjustments to hypomobile cervical spine segments, twice a week for three weeks. Cervical range of motion (CROM) was mesured using a CROM device and strength readings were measured using a hand held isometric dynamometer. Measurements were recorded on the 1st, 4th and 7th visits. All participants were required to fill in a Vernon-Mior Neck Disability Index (NDI) on the 1st and 7th visits. The data collected was analysed by a statistician. Results: Analysis of the Vernon-Mior NDI intra-group results showed that all three groups were effective in reducing cervical pain and disability. There was no statistical difference in improvement between the groups. CROM results indicated that all three groups successfully increased cervical range of motion. The combination group had the greatestimprovement, followed by the adjustment group and lastly the resistance training group. The combination group showed statistical improvements in all ranges of motion at visit 4 while this was only achieved by the resistance training group at visit 7. In the adjustment group statistical changes in flexion, extension and lateral flexion were only noted at visit 7, however in rotation, statistical improvements were noted at visit 4. Isometric dynamometer analysis showed that all 3 groups did show a statistically significant increase in cervical muscle strength. The combination group provided the greatest gains, followed by the adjustment group. The smallest gains were seen in the resistance training group. Statistical changes in the resistance training group were only measured at visit 7, while in the combination and adjustment group, these changes were noted by visit 4. Conclusion: Chiropractic adjustment was effective in increasing neck strength. Of the 3 groups, the combination treatment proved to be the most effective method of improving neck strength in individuals with cervical facet syndrome. Of the two individual treatments, chiropractic adjustment was more effective in terms of both strength gains and time taken to achieve these results, than the resistance training protocol.

Experiments were performed to determine to what extent increments in esophageal and abdominal pressure would have on arterial blood pressure during fatiguing isometric exercise. Arterial blood pressure was measured during handgrip and leg isometric exercise performed with both a free and occluded circulation to active muscles. Handgrip contractions were exerted at 33 and 70% MVC (maximum voluntary contraction) by 4 volunteers in a sitting position and calf muscle contractions at 50 and 70% MVC with the subjects in a kneeling position. Esophageal pressure measured at the peak of inspirations did not change during either handgrip or leg contractions but peak expiratory pressures increased progressively during both handgrip and leg contractions as fatigue occurred. These increments were independent of the tensions of the isometric contractions exerted. Intra-abdominal pressures measured at the peak of either inspiration or expiration did not change during inspiration with handgrip contractions but increased during expiration. During leg exercise, intraabdominal pressures increased during both inspiration and expiration, reaching peak levels at fatigue. The arterial blood pressure also reached peak levels at fatigue, independent of circulatory occlusion and tension exerted, averaging 18.5-20 kPa (140-150 mm Hg) for both handgrip and leg contrations. While blood pressure returned to resting levels following exercise with a free circulation, it declined by only 2.7-3.8 kPa after leg and handgrip exercise, respectively, during circulatory occlusion. These results indicate that straining maneuvers contribute 3.5 to 7.8 kPa to the change in blood pressure depending on body position.

Seven male subjects exercised for 1, 3, 10 and 20 min on a cycle ergometer at 20, 60 and 80% {Mathematical expression}, and then held to fatigue a sustained contraction of the quadriceps at 40% maximal voluntary contraction in order to determine what influence various levels of dynamic exercise would have on isometric function of the same group of muscles. Muscle temperature was measured before and within 15 s of the completion of the cycling to determine whether changes in muscle temperature might influence the subsequent isometric perormance. Isometric endurance was shorter as the severity of the cycling increased beyond 20% {Mathematical expression}, and as the duration of cycling increased up to 10 min. There were discrete linear relationships between muscle temperature and isometric endurance associated with cycling at 60% and 80% {Mathematical expression}. There was a direct inverse relationship between quadriceps strength after cycling and muscle temperature, yet a significant reduction in strength occurred only after cycling at 80% {Mathematical expression}. These results suggest that the encroachment on endurance and strength are controlled by different mechanisms. The heart rates during the isometric contractions were dependent on the preceding rhythmic exercise and decreased after exercise at 60 or 80% {Mathematical expression}. In contrast, the blood pressure always increased during the isometric contractions, reaching similar values at the point of fatigue, regardless of the severity of the previous rhythmic exercise. These data provide additional evidence that separate mechanisms control changes in heart rate and blood pressure.

Various opioids were used to investigate the role they might play in the cardiovascular responses to fatiguing isometric contractions. Changes in blood pressure were measured in cats anaesthetised with α-chloralose. Fatiguing isometric contractions of the hind limb muscles (ergoreceptor activation) were generated using a microprocessor controlled stimulator (50 Hz, 0.2 ms, 200-800 mV). Baroreceptor inactivation was elicited by carotid artery occlusion. Muscle contraction caused an increase in mean arterial pressure of 51 (SEM 12) mm Hg and carotid occlusion an increase of 56(9) mm Hg above resting levels in control conditions. Injection of dynorphin (0.5-5.0 μg·5 μl-1) into the cerebral aqueduct just rostra1 to the 4th ventricle eliminated the pressor response to muscular contraction (mean arterial pressure at rest, 80-118 mm Hg: on fatigue, 72-129 mm Hg) but did not affect the pressor response to carotid occlusion in the same cats. Similarly, injections of met-enkephalin (1-100 μg·5 μl-1) or β-endorphin (10-100 μg·5 μl-1) eliminated the ergoreceptor induced changes in mean arterial pressure during isometric contractions but had no effect on the changes caused by carotid occlusion. Pressor responses to nerve crush were not eliminated. These results support the suggestion that a catecholaminergic-opioidergic pathway in part mediates the cardiovascular responses to ergoreceptor afferent but probably not baroreceptor afferent input.

An isometric, zero-order (position), one dimensional pursuit tracking task was used to investigated the effects of alterations in the speed of target movement and the control/response ratio (C/R ratio) on human tracking performance. The speed of target movement was varied through different frequency sine-wave forcing functions. The C/R ratio was controlled by varying the force level required to track the target. This required force level was individually tailored I with force levels scaled to the isometric maximum voluntary contraction (MVC) of elbow extension for each subject. It was hypothesized that higher frequencies of forcing function (5 levels) and higher required force levels (5 levels) would result in degraded tracking performance. The dependent variable investigated was absolute tracking error as a proportion of the required force level for the trial. Results revealed significant main effects for both Frequency and Force, but not for any of the two- or three-way interactions. The trend was linear for Frequency, with superior tracking occurring at slower frequencies. The effect of Force level was modelled using a second-order polynomial, indicating that superior tracking occurred at the middle required force levels. Regression analysis provided a predicted optimal force level of approximately 65% extension MVC. Subjective mental workload evaluations using the Modified Cooper-Harper scale showed similar results. Results are interpreted with regards to selecting optimum system gains for human manual control. / Master of Science

The purpose of this research was to study the relationship between muscle coordination and the performance of a simple manual tracking task. The study employed an isometric, zero order, pursuit tracking task with a laterally translating, periodic sine wave forcing function. The speed of the target was varied by altering the Frequency (3 levels) of the simple sine wave. The control/response ratio for each trial was manipulated by requiring a percentage of each subject’s flexion and extension maximum voluntary contraction effort (MVC, 5 levels) to track the target. Multiple electromyograms (EMGs) of the biceps and triceps muscle groups were taken to observe flexor and extensor activity during the tracking task. Muscle modeling techniques were used to quantify the force contributions from the biceps and triceps to the observed tracking force. It was hypothesized that significant levels of co-active muscle effort would be present during the tracking task and that this co-contraction would have a unique characteristic function about the tracking conditions which yielded optimal tracking performance. The dependent measures investigated were the absolute tracking error as a proportion of the required tracking force (proportional error, PE), the absolute antagonist muscle force (AAF), and the ratio of antagonist to agonist force (co-contraction ratio, CR). Each muscle group’s maximum muscle force (MMF) required to track each condition was also determined. The experimental design was a 3 by 5 by 2 mixed factor, repeated measures ANOVA with Gender (5 male, 5 female) as the blocking variable. The ANOVA results revealed that both target Frequency and tracking Force level had significant effects on tracking error (PE). Orthogonal polynomial contrasts showed that the Frequency effect was characteristically linear while the Force effect was quadratic in nature. A polynomial regression function was used to predict PE from the Force and Frequency conditions. This model accounted for over 96% of the variance in the PE cell means. Further analysis revealed the optimal Force level for isometric tracking to be approximately 61% MVC. Analysis of the force contributions from each muscle group revealed quadratic relationships for the actual muscle force (%MMF) of the biceps during flexion and of the triceps during extension. These results show that optimal tracking performance during flexion occurs at approximately 66% of the biceps MMF and 65% of the triceps MMF during extension. Actual MMF values were consistently larger than net force values indicating that due to the presence of co-contraction, the measured force output at the wrist underestimated the actual muscle forces involved in tracking. Neither Force nor Frequency had significant effects on absolute co-activity (AAF) showing that antagonist activity remained largely constant over the tracking conditions. However, co-activity was higher for the extension phase than for the flexion phase of the task. Both Force and Frequency had significant effects on the co-contraction ratio (CR). However, no characteristic function of co-activity was found to explain the optimal tracking performance at median levels of flexion and extension force. CR increased with increasing target speed (Frequency) while it decreased with higher tracking Force levels. Since antagonist activity (AAF) remained almost constant, these results for CR must be due to changes in the level of agonist activity needed to perform the tracking task. Higher co-contraction was also found during decreasing force production (release) than for increasing force production (exertion). Since there was no significant difference in tracking error for these parts of the task, co-activity may serve to facilitate tracking performance by controlling the rate of force release. / Master of Science

An isometric, zero-order, two-dimensional pursuit tracking task utilizing a tracking path that incorporated both linear and circular segments was used to examine the effects of variation in force magnitude, force direction, and direction of target movement upon tracking performance. A contralateral force-matching procedure was also employed to assess the effects of variation in force level and force direction upon force discrimination capabilities. Increases in force demand were hypothesized to result in degradation of both force discrimination capabilities and accuracy of tracking performance. Variation in force direction was hypothesized to result in tracking performance degradation and force discrimination deterioration that were inversely related to strength-related differences associated with each direction. It was hypothesized that linear tracking performance during inward (force-decreasing) movement of the target would be superior to linear tracking performance in the outward (force-increasing) direction. Finally, it was hypothesized that the direction-sensitive strength:demand ratio, SDR, (a measure of the relationship between strength and the magnitude of force demand) would correlate with both tracking performance and force discrimination measures and that force discrimination measures would correlate with tracking performance. The findings robustly supported the hypothesized Force Level effect. The strength-related Force Direction effects were also supported, but somewhat less consistently than those for Force Level. As also hypothesized, linear inward tracking was superior to linear outward tracking. Previously unreported direction-of-movement effects were found for the circular tracking conditions. When measured along the path, clockwise (CW) tracking was superior to counterclockwise (CCW) tracking with the differences being greatest at the higher force level and in the longitudinal (forward and aft) directions. CCW tracking was superior to CW tracking when measured orthogonal to path. The hypothesized correlations among SDR, two of the three force discrimination measures, and tracking performance were found to be small but significant. / Ph. D.

Diabetic patients are prone to complications and need foot care education. The purposes of this study were to (1) examine the effectiveness of instruction on knowledge of foot care in diabetics, and practice of foot care in diabetics, and (2) examine the relationship between health promoting behaviors and foot care practices. The theoretical framework for this study was Nola Pender's Health Promotion Model. The sample for the study consisted of 69 individuals, ages 18 and older with diabetes mellitus (Type I or Type II).Control and experimental groups completed a demographic sheet and Pender's Health Promoting Lifestyle Profile. The control group received the traditional intervention of a written handout (Novo Nordisk Pharmaceuticals, Inc.) and a packet including an emery board, moisturizing lotion, and a hand-held mirror. The experimental group received a specialized nursing intervention of one-on-one instruction along with a written handout, and a packet including an emery board, moisturizing lotion, and a handheld mirror. Both groups were informed of a $10.00 stipend obtainable and paid by the researcher, for those who completed the study. Two weeks following the office visit, both groups received by mail: a follow-up letter, post-tests on knowledge (Knowledge Questionnaire) and practice (Practice Profile), and a stamped return envelope.There was a significant difference between the control group and the experimental group in knowledge of foot care. There was no significant difference between the control group and the experimental group in practices of foot care. There was a significant, positive correlation (r=.306, p=.012) between the practices of health promoting behaviors and foot care practices. Also, educational level was positively correlated (r=.432, p=.001) with knowledge of foot care.Several studies have been done on diabetic foot care instruction but few have been done to compare different methods of instruction with foot care knowledge and practice. One-on-one education provides an opportunity for the learner to play an active role in the discussion of alternative methods of foot care while allowing for immediate feedback from the nurse educator. Packets that include a well-written instruction sheet and foot care items for patient use can be helpful when educating patients about foot care. / School of Physical Education

The purposes of this study are 1) to investigate the development of physical fitness through the medium of fifteen-minute exercise routines in junior college physical education classes; 2) to determine the relationship between each of four exercise routines and the improvement of physical development in a specific body area; and 3) to compare the results of intensive, isometric, calisthenic, and continuous exercise routines to determine if any one routine was of greater value to three alternate routines in assisting the individual to attain a higher degree of physical fitness development.

This study investigates the effects of isotonic and isometric exercises on heart rate and blood pressure and seeks to determine the relationship of these effects to physical work capacity.