The objective of the present study was to examine the relationship between maximal effort force production and anthropometric measures of upper-arm volume. Thirty healthy young participants (15 women) performed 5 isokinetic concentric and eccentric maximal effort elbow flexor/extensor contractions on separate days. Measures of arm length, circumference, and skinfold/subcutaneous fat thickness were used to obtain a measure of arm volume, modeled as 2 separate right-angle frustra. Single-variable regression analyses demonstrated significant (P < .001) second-order polynomial relationships between maximal effort elbow flexor and extensor force with arm volume (r 2 = .63–.86). The major findings demonstrated that strong and positive relations between maximal force production and estimates of limb volume can be observed using nonlinear modeling and a closer geometric representation of the exercising limb.
Danny M. Pincivero, Rachael R. Polen and Brittany N. Byrd
Danny Pincivero, Joe H. Gieck and Ethan N. Saliba
A treatment and rehabilitation protocol was implemented on a university football player sustaining a second-degree lateral ankle sprain. The initial treatment plan involved the application of the RICE principle (rest, ice, compression, and elevation). This particular rehabilitation protocol was aimed at restoring range of motion and function at the earliest possible time with the use of a cryokinetic technique developed by Knight and with progressive exercise. The subject in this case study returned to full participation 6 days postinjury. The results from this report indicate that a program of cryokinetics and functional progressive exercise performed within pain-free limits can greatly enhance the return of an athlete to competition.
Tina L. Claiborne, Charles W. Armstrong, Varsha Gandhi and Danny M. Pincivero
The purpose of this study was to determine the relationship between hip and knee strength, and valgus knee motion during a single leg squat. Thirty healthy adults (15 men, 15 women) stood on their preferred foot, squatted to approximately 60 deg of knee flexion, and returned to the standing position. Frontal plane knee motion was evaluated using 3-D motion analysis. During Session 2, isokinetic (60 deg/sec) concentric and eccentric hip (abduction/adduction, flexion/extension, and internal/external rotation) and knee (flexion/extension) strength was evaluated. The results demonstrated that hip abduction (r 2 = 0.13), knee flexion (r 2 = 0.18), and knee extension (r 2 = 0.14) peak torque were significant predictors of frontal plane knee motion. Significant negative correlations showed that individuals with greater hip abduction (r = –0.37), knee flexion (r = –0.43), and knee extension (r = –0.37) peak torque exhibited less motion toward the valgus direction. Men exhibited significantly greater absolute peak torque for all motions, excluding eccentric internal rotation. When normalized to body mass, men demonstrated significantly greater strength than women for concentric hip adduction and flexion, knee flexion and extension, and eccentric hip extension. The major findings demonstrate a significant role of hip muscle strength in the control of frontal plane knee motion.
Gloria M. Beim, Jorge L. Giraldo, Danny M. Pincivero, Matthew J. Borror and Freddie H. Fu
The purpose of this study was to compare electromyographic (EMG) activity of the abdominal muscles between the crunch exercise and five other popular abdominal exercises. Surface EMG recordings of four muscles (upper rectus, lower rectus, external oblique, and internal oblique) of the anterior abdominal wall were collected and analyzed on 20 healthy, male volunteers. EMG activity was recorded during execution of the abdominal crunch, the sit-up, and exercises performed with the Abflex machine, the AbRoller, the Nordic Track Ab Works, and the Nautilus crunch machine. The results indicate that the crunch exercise is comparable to the five other abdominal exercises with respect to muscle activation of the internal and external abdominal oblique muscles. Activation of the upper rectus abdominal muscles appears to be best achieved with the Abflex machine, whereas the crunch exercise is superior to the sit-up for activation of the upper and lower rectus abdominal muscles.