Karate Group Research Articles

ACOMPARISON OF LOWER-BODY FLEXIBILITY, STRENGTH, AND KNEE STABILITY BETWEEN KARATE ATHLETES AND ACTIVE CONTROLS

The purposes of this study were to compare the lower-body flexibility, strength, and knee stability of karate athletes against that of non-karate controls and to determine whether regular karate training results in adaptations that may result in an increased risk for knee injury. Flexibility measurements included knee flexion and extension, hip flexion and extension, hip internal and external rotation, and foot inversion and eversion. Nine karate athletes (4 women and 5 men, age = 24.3 ± 6.7 years) and 15 active, non-karate controls (7 women and 8 men, age = 22.1 ± 3.2 years) participated. No subjects reported recent knee surgery or chronic or acute knee pain. Concentric quadriceps and hamstrings strength and endurance were measured using a Biodex II isokinetic dynamometer at 60° ·s-1 and 180°·s-1. Eccentric strength was measured at 150°·s-1 and 250 ft-lb (339 N·m). Knee stability was measured via varus and valgus stress and anterior drawer testing. Karate athletes demonstrated a significantly greater right hip flexion (p ≤ 0.05). Isokinetic testing demonstrated a significantly greater concentric right and left hamstrings peak torque at 60°·s-1, right hamstrings to quadriceps torque ratio at both 60°·s-1 and 180°·s-1, and a significantly faster time to peak torque in the hamstrings at 60°·s-1 in the karate athletes (p≤ 0.05). Eccentric isokinetic testing showed a significantly higher peak torque at 60°·s-1 in both the right and left quadriceps and hamstrings in the karate group compared to the controls (p ≤ 0.05). There were no significant differences in bilateral movement of the knees between the karate and control groups. The results indicate that this group of karate athletes may have demonstrated sport-specific adaptations in certain flexibility and strength measurements, but they showed no increased risk for knee injury.

A Comparison of Lower-Body Flexibility, Strength, and Knee Stability Between Karate Athletes and Active Controls

The purposes of this study were to compare the lower-body flexibility, strength, and knee stability of karate athletes against that of non-karate controls and to determine whether regular karate training results in adaptations that may result in an increased risk for knee injury. Flexibility measurements included knee flexion and extension, hip flexion and extension, hip internal and external rotation, and foot inversion and eversion. Nine karate athletes (4 women and 5 men, age = 24.3 +/- 6.7 years) and 15 active, non-karate controls (7 women and 8 men, age = 22.1 +/- 3.2 years) participated. No subjects reported recent knee surgery or chronic or acute knee pain. Concentric quadriceps and hamstrings strength and endurance were measured using a Biodex II isokinetic dynamometer at 60 degrees .s(-1) and 180 degrees .s(-1). Eccentric strength was measured at 150 degrees .s(-1) and 250 ft-lb (339 N.m). Knee stability was measured via varus and valgus stress and anterior drawer testing. Karate athletes demonstrated a significantly greater right hip flexion (p <or= 0.05). Isokinetic testing demonstrated a significantly greater concentric right and left hamstrings peak torque at 60 degrees .s(-1), right hamstrings to quadriceps torque ratio at both 60 degrees .s(-1) and 180 degrees .s(-1), and a significantly faster time to peak torque in the hamstrings at 60 degrees .s(-1) in the karate athletes (p <or= 0.05). Eccentric isokinetic testing showed a significantly higher peak torque at 60 degrees .s(-1) in both the right and left quadriceps and hamstrings in the karate group compared to the controls (p <or= 0.05). There were no significant differences in bilateral movement of the knees between the karate and control groups. The results indicate that this group of karate athletes may have demonstrated sport-specific adaptations in certain flexibility and strength measurements, but they showed no increased risk for knee injury.

Externalizing and Oppositional Behaviors and Karate-do: The Way of Crime Prevention

Childhood disruptive behaviors can be precursors to later deviance. To verify the efficacy of karate, a complex psychomotor activity that enhances self-regulation and executive skills, as an intervention for externalizing behaviors, 16 children, ranging in age from 8 to 10 years, and meeting diagnostic criteria for oppositional defiant disorder were studied. Eight were randomly assigned to a 10-month Wa Do Ryu karate program, whereas 8 children received no intervention. The children were assigned to a larger karate class, composed of typically developing youngsters. Three domains of temperament--intensity, adaptability, and mood regulation--were measured at the beginning and the end of the training period in all 16 participants. A significant improvement in temperament scale scores was measured in the karate group for all tested items compared to controls. Karate, when properly taught, can be a useful adjunct in multimodal programs aimed at externalizing behavior reduction.

Ballistic movement performance in karate athletes.

Nine male karate athletes and 13 untrained men did maximal voluntary isometric (MVC) and ballistic elbow extension actions, the latter unloaded (L0) and against a load equal to 10% MVC (L10). The karate group achieved greater (P < 0.05) isometric (32%) and ballistic action peak torque with L0 (30%) and L10 (40%). With L10 the ratio of ballistic action to isometric action, peak torque was 13% greater in the karate group, indicating a load specific training adaptation. With L0 the corresponding ratio did not differ significantly between groups. Ballistic action peak rate of torque development (51%, 51%) and peak acceleration (15%, 9%) with L0 and L10, respectively, were greater in the karate group. In contrast, peak velocity and movement time did not differ significantly between groups. Electromyographic recordings of agonist triceps and antagonist biceps were made during the isometric and ballistic actions. Since ballistic actions (L10) were initiated from a preloaded condition, the occurrence and duration of premovement agonist depression were monitored. In ballistic actions there were no group differences in agonist activation, the ratio of ballistic to isometric action agonist activation, or antagonist coactivation. Premovement agonist depression occurred infrequently in both groups, with no group differences. It is concluded that karate athletes have enhanced elbow extension ballistic performance, but it could not be related to amplified agonist activation, altered antagonist activation, or more frequent occurrence of agonist premovement depression.

The Effect of Karate Training on Flexibility, Muscle Strength, and Balance in 8- to 13-Year-Old Boys

The effect of 6 months of twice weekly karate training on flexibility, balance, and strength was evaluated in 14 boys who perform karate as beginners (age M = 10.3 ± 1.8) and a group of the same age who had never been involved in martial arts (n = 10; age M = 10.9 ± 1.4). All subjects were pretested and posttested on the following: flexibility of upper extremity (shoulder), hamstrings and quadriceps; strength, including handgrip strength and concentric flexion/extension of quadriceps; and balance, with eyes either open or closed. After 6 months, the tests were evaluated and compared by groups. The results showed the karate group made significant gains on quadriceps flexibility and balance with eyes closed. By improving flexibility, balance, and strength, karate improves three of the basic fitness components that are very important for preventing sport injuries in the growing years.