current study, Beattie and Flanagan 26 also observed that the DJ-40 reactive strength test was unable to detect the SWC. The observed CV was greater than the calculated SWC. However, other studies have observed much lower CV for RSI in the drop jump. Markwick et al 27 observed RSI CVs of 2.1% to 3
Thomas M. Comyns, Eamonn P. Flanagan, Sean Fleming, Evan Fitzgerald and Damian J. Harper
Alexander Törpel, Tim Becker, Angelina Thiers, Dennis Hamacher and Lutz Schega
Context:The use of isokinetic dynamometers playing an important role in different settings of sports and medicine. Therefore, a high reliability of these devices is required. Objective: The aim of this study was to examine the intersession reliability of the dynamometer BTE PrimusRS regarding to the isolated single-joint exercises extension/flexion of the knee and elbow for isokinetic testing. Design: Intersession reliability. Setting: Clinical settings and sports science. Participants: 16 young male students. Intervention: The testing protocol includes 5 consecutive repetitions (concentric/concentric) at a velocity of 60°/s for the exercises. Main Outcome Measures: Raw data of torque curves were used to determine the peak torque. Reliability was evaluated with the intraclass correlation coefficient (ICC), the limits of agreement (LoA), and the bias and the variability of measurements (V). Results: High ICC values (.954-.991) were found for the used exercises. However, the LoAs yielded up to over 16 Nm and the V yielded up to nearly 9 % in several testing exercises, indicating poor absolute reliability. Conclusion: The BTE PrimusRS shows good to excellent reliability. However, regarding the absolute measures of reliability, the users must decide as experts in their fields whether this reliability is sufficient for their purposes.
Dusa Marn-Vukadinovic and Helena Jamnik
Valid patient-based outcome instruments are necessary for comprehensive patient care that focuses on all aspects of health, from impairments to participation restrictions.
To validate the Slovenian translation of Medical Outcome Survey (MOS) Short Form Health Survey (SF-36) and to assess relations among various knee measurements, activity tested with Oxford Knee Score (OKS) and health-related quality of life as estimated with SF-36 domains.
Descriptive validation study.
Isokinetic laboratory in outpatient rehabilitation unit.
101 subjects after unilateral sport knee injury.
All subjects completed the SF-36 and OKS, and isokinetic knee-muscle strength output at 60°/s was determined in 78 participants. Within a 3-d period, 43 subjects completed the SF-36 and OKS questionnaires again.
Main Outcome Measures:
Reliability testing included internal consistency and test–retest reliability. Correlations between SF-36 subscales and OKS were calculated to assess construct validity, and correlation between SF-36 subscales and muscle strength was calculated to assess concurrent validity.
Chronbach α was above .78 for all SF-36 subscales. ICCs ranged from .80 to .93. The correlation between OKS and the physical-functioning subscale, showing convergent construct validity, was higher (r = .83, P < .01) than between OKS and mental health (r = .50, P < .01), showing divergent construct validity. Knee-extensor weakness negatively correlated with physical-functioning (r = −.59, P < .01) and social-functioning (r = −.43, P < .01) subscales.
The Slovenian translation of the SF-36 is a reliable and valuable tool. The relationships between knee-muscle strength and activity and between knee-muscle strength and SF-36 subscales in patients after sport knee injury were established.
Christopher Kuenze, Moataz Eltouhky, Abbey Thomas, Mark Sutherlin and Joseph Hart
Collecting torque data using a multimode dynamometer is common in sports-medicine research. The error in torque measurements across multiple sites and dynamometers has not been established.
To assess the validity of 2 calibration protocols across 3 dynamometers and the error associated with torque measurement for each system.
3 university laboratories at separate institutions.
2 Biodex System 3 dynamometers and 1 Biodex System 4 dynamometer.
System calibration was completed using the manufacturer-recommended single-weight method and an experimental calibration method using a series of progressive weights. Both calibration methods were compared with a manually calculated theoretical torque across a range of applied weights.
Main Outcome Measures:
Relative error, absolute error, and percent error were calculated at each weight. Each outcome variable was compared between systems using 95% confidence intervals across low (0–65 Nm), moderate (66–110 Nm), and high (111–165 Nm) torque categorizations.
Calibration coefficients were established for each system using both calibration protocols. However, within each system the calibration coefficients generated using the single-weight (System 4 = 2.42 [0.90], System 3a = 1.37 [1.11], System 3b = –0.96 [1.45]) and experimental calibration protocols (System 4 = 3.95 [1.08], System 3a = –0.79 [1.23], System 3b = 2.31 [1.66]) were similar and displayed acceptable mean relative error compared with calculated theoretical torque values. Overall, percent error was greatest for all 3 systems in low-torque conditions (System 4 = 11.66% [6.39], System 3a = 6.82% [11.98], System 3b = 4.35% [9.49]). The System 4 significantly overestimated torque across all 3 weight increments, and the System 3b overestimated torque over the moderate-torque increment.
Conversion of raw voltage to torque values using the single-calibration-weight method is valid and comparable to a more complex multiweight calibration process; however, it is clear that calibration must be done for each individual system to ensure accurate data collection.
Brianna M. Papotto, Thomas Rice, Terry Malone, Timothy Butterfield and Tim L. Uhl
Context: Shoulder external rotators are challenged eccentrically throughout the deceleration phase of throwing, which is thought to contribute to overuse injuries. To evaluate the effectiveness of intervention programs, as well as identifying deficits, reliable and responsive measures of isometric and eccentric shoulder external rotation are necessary. Previously, isometric measures have primarily tested a single position, and eccentric measures have not been found to have high reliability. Objective: To examine the between-days reliability of multiple-angle isometric and dynamic eccentric isokinetic testing of shoulder external rotation. Design: Repeated measures. Participants: 10 healthy subjects (age 30 ± 12 y, height 166 ± 13 cm, mass 72 ± 10 kg). Main Outcome Measures: Average isometric peak torque of shoulder external rotation at 7 angles was measured. From these values, the angle of isometric peak torque was calculated. Dynamic eccentric average peak torque, average total work, and average angle of peak torque were measured. Results: Between-days reliability was high for average peak torque during isometric contractions at all angles (ICC ≥ .85), as it was for dynamic eccentric average peak torque (ICC ≥ .97). The estimated angle of isometric peak torque (ICC ≤ .65) was not highly reliable between days. The average angle of peak torque from the eccentric testing produced inconsistent results. Average total work of dynamic eccentric shoulder external rotation was found to be highly reliable between days (ICC ≥ . 97). Conclusion: Aspects of force such as peak torque and total work in isometric and eccentric testing of the shoulder external-rotator muscles can be measured reliably between days and used to objectively evaluate shoulder strength and identify changes when they occur. Angle measurements of peak torque could provide insight into the mechanical properties of the posterior shoulder muscles but were found to be inconsistent between days.
Jim Wilcox, Rich Larson, Kevin M. Brochu and Avery D. Faigenbaum
The purpose of this investigation was to determine whether the performance of explosive-force movements before bench-press exercise would improve 1-repetition-maximum (1RM) strength.
Twelve male college athletes participated in 3 testing sessions separated by at least 5 days of rest. During each testing session, the 1RM was assessed on the bench-press exercise. After a general warm-up, subjects performed a specific warm-up that consisted of submaximal sets with increasing loads on the bench-press exercise before attempting a 1RM lift. During the first testing trial, subjects performed a series of 1RM attempts with increasing loads until their 1RM was determined. During the second and third testing trials, subjects performed in a counterbalanced randomized order either 2 plyometric push-ups or 2 medicine-ball (3 to 5 kg) chest passes 30 seconds before each 1RM attempt.
Analysis of the data revealed that 1RM bench-press strength was significantly greater after plyometric push-ups (P = .004) or chest passes (P = .025) in comparison with the first trial (123.8 ± 23.5 kg and 124.0 ± 24.1 kg vs 120.9 ± 23.2 kg, respectively).
These data suggest that an acute bout of low-volume, explosive-force upper body movements performed 30 seconds before a 1RM attempt might enhance bench-press performance in athletic men.
William Holcomb, Mack D. Rubley and Tedd J. Girouard
Electrical stimulation using simultaneous application of two current types for multiple effects is a current treatment option, but the effect of this treatment is not currently known.
To compare isometric knee extension torque when using neuromuscular electrical stimulation (NMES) in combination with High Voltage Pulsed Current (HVPC) versus NMES alone during three contraction conditions of quadriceps.
Counterbalanced, within-subjects design to test independent variables, stimulation protocol, and contraction condition; ANOVA to analyze dependent variable, peak torque.
Athletic Training Research Laboratory. Participants: 14 healthy subjects (7 male and 7 female, age = 21.9 ± 2.0 yr, height = 173.4 ± 10.1cm, weight = 76.1 ± 16.7 kg).
Participants performed three contraction conditions during two stimulation protocols.
Main Outcome Measure:
Peak isometric knee extension torque.
The main effect for Stimulation Protocol was not significant: F1,26 = .01, P = .94.
Simultaneous application of HVPC with NMES does not facilitate the neuromuscular response but may provide an efficient treatment when managing atrophy, strength loss, pain, and edema associated with reconstructive surgery.
Barıs Seven, Gamze Cobanoglu, Deran Oskay and Nevin Atalay-Guzel
the same as the assessment and were not performed with maximal effort. After the trials, a 20-second resting time was provided. Angular velocity adjustment depends on the joint and parameter evaluated. 17 Strength tests are performed at low speeds, while power and endurance tests are performed at
Francisco J. Vera-Garcia, Diego López-Plaza, Casto Juan-Recio and David Barbado
the core to the limbs) and are normally performed in single-leg stance, as for example, the 3-Plane Core Strength Test and the Star Excursion Balance Test 2 , 17 , 21 , 23 ; and (3) trunk muscle fitness tests, which generally measure isometric trunk endurance, such as the Biering-Sørensen Test, 17
Aurora de Fátima G.C. Mafra Cabral, Marcelo Medeiros Pinheiro, Charlles H.M. Castro, Marco Túlio De Mello, Sérgio Tufik and Vera Lúcia Szejnfeld
spent to get up an armless chair, walk 3 m, stroll and walk back, and sit back in the chair, all without hand support ( Podsiadlo & Richardson, 1991 ); the handgrip strength test (HST), performed using a dynamometer (Jamar) and using the protocol recommended by the American Society of Hand Therapists