The purpose of this study was to assess the effect of interferential current (IFC) on perceived pain and serum Cortisol levels in subjects with delayed onset muscle soreness (DOMS). DOMS was induced in 10 subjects through repeated eccentric contractions of the elbow flexors. Forty-eight hours later subjects were evaluated. Starting at t = 0:00, blood samples were withdrawn from a superficial vein every 5 min for 65 min. At t = 0:05, subjects received IFC of 10 bps or IFC of 100 bps. Perceived pain levels were evaluated prior to catheter insertion and at t = 0:35, 0:50, and 0:65. Two mixed-model analyses of variance revealed a significant decrease in perceived pain scores across time for both treatment groups but no significant difference in serum Cortisol for the two groups. It was concluded that IFC of high and low beat frequency is effective in controlling the pain of DOMS but does not elicit a generalized stress response as indexed by increasing serum Cortisol levels.
Randy J. Schmitz, David E. Martin, David H. Perrin, Ali Iranmanesh and Alan D. Rogol
Sandra J. Shultz and David H. Perrin
Joshua M. Drouin, Peggy A. Houglum, David H. Perrin and Bruce M. Gansneder
To determine the relationship between weight-bearing (WB) and non-weight-bearing (NWB) joint reposition sense (JRS) and a functional hop test (FH) and to compare performance on these parameters between athletes and nonathletes.
Repeated-measures ANOVA and Pearson correlations.
40 men (age = 20.8 ± 1.7 y; ht = 176.9 ± 5.8 cm; wt = 82.6 ± 9.5 kg): 20 lacrosse players and 20 nonathletes.
Main Outcome Measures:
Ability to actively reproduce 30° of knee flexion in the WB and NWB conditions and functional performance on a single-leg crossover-hop test.
No significant correlations were observed between JRS and FH in athletes and nonathletes. No significant differences were observed between athletes and nonathletes in JRS. All participants were significantly more accurate at WB than at NWB JRS.
There appears to be no relationship between WB or NWB JRS and functional performance, regardless of one’s physical activity level
Joseph E. Szczerba, Julie N. Bernier, David H. Perrin and Bruce M. Gansneder
The purpose of this study was to estimate intertester reliability of active and passive ankle joint position sense measurements in uninjured subjects. Subjects were 10 males and 10 females. Active and passive ankle joint position sense was assessed by two testers. Each subject was positioned supine on a modified examination table with his or her ankle placed in 25° of plantar flexion. Joint position sense (IPS) measurements, on two separate occasions, were recorded in degrees of error from four predetermined test positions. Test order was counterbalanced according to mode (active/passive) and test position. Two trials were performed for each sequence and the average of the two was recorded for analysis. The results revealed that both the active and passive JPS protocols yielded poor to moderate intertester reliability. It was concluded that further research is needed to develop reliable protocols for testing joint position sense of the ankle joint.
Carl G. Mattacola, David H. Perrin, Bruce M. Gansneder, Jennifer D. Allen and Cheryl A. Mickey
This study evaluated a visual analog scale (VAS) and a graphic rating scale (GRS) for the measurement of pain following delayed onset muscle soreness (DOMS) and following treatment for the symptoms of DOMS. Data from two studies were used to evaluate the scales. Pain intensity was assessed prior to and following induction of DOMS and immediately before and after each treatment session. In Study 1, subjects were randomly assigned to receive a 20-min ice pack followed by a 7-min sham ultrasound treatment or a 20-min ice pack followed by a 7-min nonthermal ultrasound treatment. In Study 2, subjects received a 20-rain microcurrent neuromuscular stimulation (MENS) treatment or a 20-min sham MENS treatment. In both studies, significant differences were found between the VAS and GRS scales for pretest conditions on Days 1 and 2 for all subjects. There were no significant differences between any other days or tests. The differences on Day 1 and Day 2 were attributed to the novelty of filling out the scales. Therefore, a. visual analog or graphic rating scale can be used to evaluate pain intensity following DOMS when repeated measurement is involved, although consideration should be given to potential differences the first one or two times the scales are completed.
Thomas W. Kaminski, David H. Perrin, Carl G. Mattacola, Joseph E. Szczerba and Julie N. Bernier
This study examined the test-retest reliability of a prototype device used to measure ankle inversion and eversion isokinetic average torque values. The purpose of this paper was to illustrate a situation where common isokinetic measures were reliable but not valid. Concentric and eccentric average torque was assessed at 90 deg/s on the Kin Com II dynamometer using 14 healthy subjects in two sessions; a manufactured prototype ankle inversion/eversion attachment device was used. Reliability was assessed by performing separate intraclass correlations (ICC 2,1) on the results. The data indicated that the average torque calculated from the clockwise direction was consistently higher than those values from the counterclockwise direction, regardless of ankle movement or side measured. The validity of this prototype device to accurately measure average torque for these two ankle motions is questionable. This finding demonstrates a situation where the measures appear to be reliable while the validity of the device used to obtain the measures is suspect.
Anthony S. Kulas, Randy J. Schmitz, Sandra J. Shultz, Mary Allen Watson and David H. Perrin
Although leg spring stiffness represents active muscular recruitment of the lower extremity during dynamic tasks such as hopping and running, the joint-specific characteristics comprising the damping portion of this measure, leg impedance, are uncertain. The purpose of this investigation was to assess the relationship between leg impedance and energy absorption at the ankle, knee, and hip during early (impact) and late (stabilization) phases of landing. Twenty highly trained female dancers (age = 20.3 ± 1.4 years, height = 163.7 ± 6.0 cm, mass = 62.1 ± 8.1 kg) were instrumented for biomechanical analysis. Subjects performed three sets of double-leg landings from under preferred, stiff, and soft landing conditions. A stepwise linear regression analysis revealed that ankle and knee energy absorption at impact, and knee and hip energy absorption during the stabilization phases of landing explained 75.5% of the variance in leg impedance. The primary predictor of leg impedance was knee energy absorption during the stabilization phase, independently accounting for 55% of the variance. Future validation studies applying this regression model to other groups of individuals are warranted.