Long-duration submaximal exercise conditioning in hemodialysis patients.

Objective changes in exercise tolerance were evaluated in five chronic hemodialysis patients (HD) following a ten week aerobic treadmill exercise conditioning program designed to exercise patients at a level approximating their anaerobic threshold (AT). This exercise conditioning program resulted in a 21% increase in peak oxygen consumption, an increase in test duration from 17.40 +/- 1.26 to 22.60 +/- 0.87 min (P less than 0.025), and an increase in AT from 0.81 +/- 0.08 to 0.97 +/- 0.08 1/min (P less than 0.05). These physiologic changes in exercise tolerance resulted in an overall increase in work capacity permitting the HD patient to perform a larger portion of the imposed work load aerobically.

The nature of torque "overshoot" in Cybex isokinetic dynamometry.

Transient peaks or "spikes" frequently appear in the initial segments of torque curves recorded with the Cybex isokinetic dynamometer. The purpose of this investigation was to determine whether these spikes represent artifact or transient initial surges of true muscular force output. Cinematographic analysis using both inert weights and a human subject as the source of torque input to the Cybex revealed that the dynamometer's input lever initially exceeded the pre-set angular velocity by an amount ranging from 11% (inert weight; pre-set Cybex velocity = 180 degrees/s) to 200% (human hip abduction; pre-set velocity = 30 degrees/s). The majority of this "overspeeding" occurred in the latter part of the free acceleration period, prior to the engagement of the dynamometer's resistance mechanism. The remainder occurred in the initial part of the elastic loading phase, just after resistance had engaged. A sharp deceleration of the overspeeding lever and the affixed weight or limb then followed in response to the dynamometer's continuing build-up of resistance. Simultaneous with this deceleration, a prominent torque spike was recorded that superseded the correct (mechanical equilibrium) torque value. Within our error of measurement, the deceleration observed in the film quantitatively accounted for all of the "overshoot" torque, i.e., that amount of the spike that exceeded the correct value. It was concluded that such prominent, initial torque spikes represent inertial forces and should not be confused with true muscular tension development.

Pre-participation sports assessment--an objective evaluation.

The yield from a pre-participation sports examination consisting of a review of the medical history, routine physical examination, musculoskeletal examination, laboratory screening and an assessment of fitness by evaluation of body composition, flexibility, and muscular strength testing was studied. There were 701 students evaluated. Two students (0.3%) were excluded from participation because of medical problems and seven (1%) because of orthopedic problems. Sixty students (8.6%) were referred for additional medical evaluation. Thirty-five students (5.0%) required further orthopedic evaluation. All of the students who required additional evaluations were eventually granted permission to participate. The review of the medical history was positive in seven of the restricted students and 40 of the referred students. The routine physical examination was normal in the two restricted students and abnormal in 14 of the referred students. The musculoskeletal examination was abnormal in all of the students restricted or referred for orthopedic problems. The assessment of physical fitness revealed that 32% of the students had excessive body fat, 10% to 15% of both boys and girls had excessive muscle tightness in either the upper or lower body and approximately 5% of the students had weakness in hip abductors or flexors. Significant unilateral strength deficits were also found. When performed for the purpose of restricting participation or referring students for additional evaluation, the medical history and musculoskeletal examination are the components of the pre-participation sports examination with the highest yield. Additionally, the aspects of the examination which related to fitness revealed a significant number of abnormalities.

Neurophysiologic inhibition of strength following tactile stimulation of the skin.

A modified shoulder abduction manual muscle test was incorporated in this study to demonstrate strength changes following tactile stimulation of the skin. Resistance was applied to the distal radioulnar joint and the stimulus (scratching) was applied inferior to the clavicle on the clavicular head of the pectoralis major muscle after maximum contraction. An electromechanical device quantified the isotonic (eccentric) measurements. A standard dynamometer system (Cybex II) was used to measure isometric strength. The nondominant side was used as the "control." Two populations, a normal (random) and a strong (athletic) group, were studied. Twenty-three persons (52% women, 48% men; mean age, 27 years; mean height, 67 inches (170 cm); and mean weight, 147 lb (66.7 kg)) were in the "normal" group and 17 persons (100% men; mean age, 25 years; mean height, 74 inches (188 cm); and mean weight, 215 lb (97.5kg)) were in the "strong" group. The random population showed a 19% decrease in strength following tactile stimulation as measured by the manual muscle testing unit; the athletic population showed a 17% decrease in strength. With the isometric measurements, the random population had an 8% decrease in mean strength following the scratch but the athletic population showed no significant decrease. The capability to quantify objectively manual muscle tests is discussed in relation to the importance of the proximal musculature.

The relationship between subjective and objective measurements of strength *.

Manual muscle testing is utilized by physicians and physical therapists to aid in the diagnosis and evaluation of pathology.' The basis of a diagnosis or the modification of a treatment program is dependent upon the clinician's perception of a patient's strength. This inherent subjectivity of manual muscle testing often leads to questionable findings in a medical examination. Factors such as sex, age, height, and weight serve only to increase the subjectivity of this evaluation This study demonstrates the use of a new manual muscle testing unit (MMTU) to quantify muscle strength objectively. The results of the MMTU were compared to a clinician's subjective evaluation of the stronger limb. In addition, the data obtained with the MMTU were analyzed to investigate further what constitutes a significant strength deficit. The MMTU's ability to differentiate strength differences and deficits demonstrates how manual muscle testing can assume a refined role in the evaluation of muscle strength. J Orthop Sports Phys Ther 1980;2(1):15-19.

Effect of exercise on lipid metabolism and dietary intake in hemodialysis patients.

In conclusion, a 10 wk exercise conditioning program in stable chronic hemodialysis patients resulted in improved exercise endurance without apparent adverse effects on nutritional status or lipid metabolism. Changes were observed suggesting a beneficial effect on carbohydrate and bone metabolism. The exercise-induced rise in serum creatinine may reflect an increase in muscle mass.