Gael Guilhem, Christophe Cornu, Arnaud Guével
Context: Resistance exercise training commonly is performed against a constant external ioad (isotonic) or at a constant velocity (isokinetic). Researchers comparing the effectiveness of isotonic and isokinetic resistance-training protocols need to equalize the mechanical stimulus (work and velocity) applied.
Objective: To examine whiether the standardization protocol could be adjusted and applied to an eccentric training program.
Design: Controlled laboratory study.
Setting: Controlled research laboratory. Patients or Other Participants: Twenty-one sport science male students (age = 20.6±1.5 years, height = 178.0 ±4.0 cm, mass = 74.5 ±9.1 kg).
Intervention(s): Participants performed 9 weeks of isotonic (n = 11 ) or isokinetic (n = 10) eccentric training of knee extensors that was designed so they would perform the same amount of angular work at the same mean angular velocity.
Main Outcome Measure(s): Angular work and angular velocity.
Results: The isotonic and isokinetic groups performed the same total amount of work (-185.2 ±6.5 kJ and -184.4 ±8.6 kJ, respectively) at the same angular velocity (21 ± 17s and 22°/s, respectively) with the same number of repetitions (8.0 and 8.0, respectively). Bland-Altman analysis showed that work (bias = 2.4%) and angular velocity (bias = 0.2%) were equalized over 9 weeks between the modes of training.
Conclusions: The procedure developed allows angular work and velocity to be standardized over 9 weeks of isotonic and isokinetic eccentric training of the knee extensors. This method could be useful in future studies in which researchers compare neuromuscular adaptations induced by each type of training mode with respect to rehabilitating patients after musculoskeletal injury.
Key Words: resistance exercise, muscle strength, knee extensors.
Uganet Hernández Rosa, Jorge Velasquez Tlapanco, Catalina Lara Maya S Enrique Villarreal Ríos, Lidia Martínez González, Emma Rosa Vargas Daza y Liliana Galicia Rodríguez
Reumatol Clin. 2012:8(1):10-14
Introduction: Osteoarthritis is a chronic joint disease; isometric exercise leads to the development of mechanical work and isokinetic exercise leads to better joint mobility.
Objectives: To compare the effectiveness of isometric versus isokinetic therapeutic exercises in patients with knee osteoarthritis.
Material and methods: Quasiexperimental study in a population of 45 to 75 year old patients with a diagnosis of knee osteoarthritis. Group 1 (experimental) was put under isokinetic exercises and group 2 (control) under isometric exercises. The sample size was of 33 patients per group; the allocation to the experimentation or control group was nonrandom, but stratified by degrees of knee osteoarthritis.
The effectiveness of the exercise was measured in three dimensions; muscle strength, joint range and pain. The intervention lasted eight weeks and the physical activity was carried out every third day. The statistical analysis included averages, standard deviation, pereentage, Chi square test, z test for two populations, t test for two independent populations and twin t test.
Results: The analysis of muselé strength comparing the eategories independently demonstrates differenees at 8 weeks; 33.3% of the isokinetie exercise is in the normal eategory and 15.2% in the isometric exercise (p= 0.04). There was not differenee of joint range between groups, despite finding a stage I range in 100.0% of the isokinetie group and 97.0% in the isometrie (p> 0.05) group. Pain was milder in the isokinetie exereise group at 8 weeks (p= 0.01 ).
Conclusions: Isokinetie exereises have a greater effectiveness than isometrie exercises for muscle strength and pain in patients with knee osteoarthritis. However, other studies with randomized designs are needed.
Η σπονδυλική στήλη είναι μια από τις πιο πολύπλοκες δομές του ανθρωπίνου σώματος. Διαθέτει πολυάριθμα οστά, αρθρώσεις, συνδέσμους και μυς, τα οποία συνολικά συμμετέχουν στην κινητικότητά της. Η εγγύτητα του νωτιαίου μυελού, των νευρικών ριζών και των περιφερικών νεύρων αυξάνει ακόμη περισσότερο την πολυπλοκότητά της.
