The purpose was to determine the effect of Naproxen in attenuating the symptoms (muscle soreness level) and signs (plasma CK activity and muscular strength decrement) of delayed onset muscle soreness (DOMS). Twenty subjects were randomly assigned Naproxen (500 mg BID) or placebo in a double-blind, crossover design. Two testing phases, each 8 days in duration, were separated by a washout period of 7 days. Eccentric single-leg exercises were performed on Days 1, 3 and 4 to induce DOMS in the quadriceps muscles. Perception of muscle soreness, plasma CK, and knee extensor torque were evaluated throughout each phase. Following the eccentric exercise, plasma CK levels were similarly elevated in both Naproxen and placebo conditions. After DOMS had developed, Naproxen reduced the perception of soreness on Day 3 when muscle soreness was highest. Following treatments with Naproxen, peak quadriceps torque during leg extension at 60$ sp circ$/s was higher compared to placebo, however at higher velocity (180 and 300$ sp circ$/s) peak muscle torques were similar. The data indicate that therapeutic doses of Naproxen do not prevent CK release into the plasma but decreases the perception of muscle soreness and positively influences quadriceps peak torque.

Thesis (M.S.)--Michigan State University. Dept. of Kinesiology, 2007. / Includes bibliographical references (leaves 64-66).

Presented as Thesis (Ph. D.)--University of Wisconsin--Madison, 1933. / Cover title. Reprinted from American journal of anatomy, vol. 56, no. 2 (Mar. 1935). Includes bibliographical references (p. 256).

No description available.

To study the detrimental effects of hypokinesia, many models of reduced muscular activity (i.e., reduced-use), including alterations in the size of the living environment, have been developed. Although significant structural and functional changes have been documented, the effect of reduced-use on muscle fatigability remains unclear. This project was designed to study the effects of cage-size on selected properties of rat hindlimb muscle, with particular emphasis on fatigue. Further, in view of the lack of information on the potential effect of gender, both males and females were studied. The rats were raised in either a small, conventional cage or one approximately 133 times larger. Subsequently, terminal experiments were performed to characterize the contractile properties, fiber-type composition and oxidative potential of two hindlimb muscles of the small- and large-cage-reared rats. The test muscles, soleus and extensor digitorum longus, were selected on the basis of their pronounced differences in function, usage and fiber-type composition. The results suggest that reductions in cage-size can influence the properties of skeletal muscle (specifically, muscle mass, force and fatigability) and that this effect is a function of both gender and interanimal differences. However, due to the large variability exhibited by all three factors, their overall effect will be minimal. An analysis of the response of the test muscles to a 6 min fatigue test revealed three findings. First, both muscles exhibited a wide range of fatigability, an unexpected finding particularly for soleus but in keeping with the multiplicity of factors discussed above. Second, the association observed between whole-muscle force and the electromyogram (e.m.g.) was found to be dependent upon the measure used to quantify the e.m.g., the fiber-type composition of the muscle and its degree of fatigability. And third, a coexistence of twitch potentiation and muscle fatigue was observed which also was dependent upon the fiber-type composition and the extent of fatigue. Finally, a comparison of qualitative and quantitative histochemical analyses revealed broad, overlapping ranges for oxidative enzyme activity for each of the three muscle-fiber types. This suggests that differences in fatigability usually attributed to different fiber types are not due solely to differences in oxidative potential.

Objectives: To evaluate the effect of leg muscle fatigue on balance and to determine the contributions of the somatosensory, visual, and vestibular systems to balance of apparently healthy males and females. Design: Forty-two subjects were randomly assigned to either the experimental or control groups and then subdivided based on gender resulting in four groups (10 men/women in the experimental groups and 11 men/women in the control groups). Each subject was pre-tested on the Sensory Organization Test assessment of balance. Subjects in the experimental group then underwent a Wingate Anaerobic Test to induce leg fatigue. Following the Wingate Test subjects were post-tested on the Sensory Organization Test. Subjects in the control group rested quietly for a period of seven minutes prior to post-testing. Subjects: Forty-two volunteers without recent or chronic history of lower extremity injury, neurological deficits, or balance problems participated. Main outcome measures: Ratios for the use of the somatosensory, visual, and vestibular systems and the Composite Score were calculated. A [2(Group) x 2(Gender) x 2(Test)] mixed design ANOVA was used to analyze each of the dependent variables. Results: Analysis of Composite Score demonstrated a significant Group x Test interaction (p<0.010). The breakdown of the interaction showed no significant Test effect (p-value 0.341) for the experimental group. However, there was a significant Test effect (p-value<0.010) for the control group. There were no significant effects of fatigue on somatosensory system ratio. The analysis of the visual system ratio revealed a significant main effect (p-value 0.022) for Group. Analysis of vestibular system ratio revealed a significant main effect for Test (p<0.010). Conclusions: As demonstrated by the results of the present experiment, leg muscular fatigue is associated with significantly decreased balance. In addition, fatigue does appear to have an effect on the utilization of visual and vestibular systems. / Graduation date: 2003

The purpose of this study was to compare the effects of two different velocities of eccentric work on delayed onset muscle soreness and associated factors in untrained college-aged males. Eight untrained males 21.6 (+1.7) yrs. were recruited for the study. Three subjects did not crossover design and assigned to either a 60 deg/sec or 150 deg/sec work velocity. One hundred maximal eccentric repetitions were completed separately for both legs. Exercise treatment on both legs was carried out on the Kinetic Communicator Device. Repetitions were divided into twoexercise trials. Following the exercise treatment, 10 sets of 10 repetitions with a 5 second pause between each repetition. A five week rest interval separated the range of motion (ROM) values (24, 48, 72, 122, 144 hrs.), serum creatine kinase (Ck), (pre, 24, 72, 144 hrs.), and and the results of 2 subjective soreness scales were recorded. The results of the study demonstrated no significant difference in the velocity * time interaction for Ck, ROM, and soreness perception values; however, significant findings were demonstrated for the main effect across days within each data collection except for Ck following the 150 deg/sec trial. No significant difference could be found between each leg or between both trials following each exercise treatment. The Ck'response at the faster velocity seemed to indicate that the 150 deg/sec work trial may have produced a greater amount of muscle trauma compared to the 60 deg/sec trial without significantly effecting the soreness response.

No description available.

No description available.

A number of investigators have determined the joint forces acting at the hip and knee for normal human locomotion as related to the design of prosthetic devices. This research has been extended to allow the calculation or estimation of the muscular and ligamentous forces operating at the knee joint for normal walking. The current study expanded upon the past research to evaluate the magnitude and temporal sequence of.the muscle, ligament and articular forces acting at the knee joint for a simulated skating thrust. A skilled ice hockey player was filmed in two reference planes while making a skating thrust from a laboratory force platform. The cine film data was synchronized with the force plate output to allow calculation of the orthogonal forces and moments imposed on the knee joint. The orthogonal force system was determined from a knowledge of the inertial, gravitational and reaction forces acting on the lower limb during the skating thrust. The muscle, ligament and joint forces were determined from equations derived from the conditions of joint equilibrium. The equations of equilibrium were indeterminate and had to be reduced by making assumptions from electromyographic records to allow solution. Forces were calculated for a simplified muscle and ligament system which included the hamstrings, quadriceps and gastrocnemius muscle groups, the collateral ligaments and the cruciate ligaments of the knee joint. In addition, the articular joint force, joint torque and centre of pressure of the joint force were determined. Results of the investigation revealed that the magnitude of the muscle, ligament and joint forces developed in a skating thrust were considerably greater than respective forces exerted during level walking while the temporal sequence of the skating forces was comparable to walking upstairs. The quadriceps muscle group exerted the greatest contractile force while the gastrocnemius and hamstrings groups developed much smaller forces. The largest ligament forces were developed in the collateral ligaments and the posterior cruciate ligament to maintain stability of the joint. The knee joint is subject to the combined effects of a joint force six times body weight and a large joint torque superimposed upon each other during the skating thrust and this fact is considered important when discussing the cause of menisci knee injuries. / Education, Faculty of / Curriculum and Pedagogy (EDCP), Department of / Graduate