Eccentric/concentric training of ankle evertor and dorsiflexors in recreational athletes: muscle latency and strength.

The aim of this study was to investigate the effects of a combined eccentric-concentric exercise program of the ankle evertors and dorsiflexors on the latency time of the peroneus longus and tibialis anterior muscles. Twenty-four healthy male recreational athletes were admitted to this study and were randomly assigned to either the exercise group (n = 12) or the control group (n = 12). Subjects in the exercise group performed an isokinetic exercise program of the ankle evertors and dorsiflexors in a combined eccentric-concentric mode for 3 days per week for 6 weeks. Before and after the exercise program, muscle reaction times of the peroneus longus and tibialis anterior muscles to sudden supinating maneuvers on a tilting platform, and isokinetic strength of the ankle joint musculature were evaluated. The peroneus longus and tibialis anterior reaction times showed significant (P < 0.01-0.05) reductions following six weeks of intervention in the exercise group. Additionally, eccentric peak torques for the ankle evertor and dorsiflexors represented significant (P < 0.05) increases in the exercise group compared with the control group. The results of this study suggest that it is possible to reduce peroneal and anterior tibial reaction times following a six week eccentric/concentric isokinetic training program in healthy ankles.

Acute effects of static and dynamic stretching on leg flexor and extensor isokinetic strength in elite women athletes.

The aim of this study was to explore the effects of static and dynamic stretching of the leg flexors and extensors on concentric and eccentric peak torque (PT) and electromyography (EMG) amplitude of the leg extensors and flexors in women athletes. Ten elite women athletes completed the following intervention protocol in a randomized order on separate days: (a) non-stretching (control), (b) static stretching, and (c) dynamic stretching. Stretched muscles were the quadriceps and hamstring muscles. Before and after the stretching or control intervention, concentric and eccentric isokinetic PT and EMG activity of the leg extensors and flexors were measured at 60 and 180 degrees/s. Concentric and eccentric quadriceps and hamstring muscle strength at both test speeds displayed a significant decrease following static stretching (P<0.01-0.001). In contrast, a significant increase was observed after dynamic stretching for these strength parameters (P<0.05-0.001). Parallel to this, normalized EMG amplitude parameters exhibited significant decreases following static (P<0.05-0.001) and significant increases following dynamic stretching (P<0.05-0.001) during quadriceps and hamstring muscle actions at both concentric and eccentric testing modes. Our findings suggest that dynamic stretching, as opposed to static or no stretching, may be an effective technique for enhancing muscle performance during the pre-competition warm-up routine in elite women athletes.

Reliability of a functional test battery evaluating functionality, proprioception, and strength in recreational athletes with functional ankle instability.

AIM: In contrast to the single evaluation methods used in the past, the combination of multiple tests allows one to obtain a global assessment of the ankle joint. The aim of this study was to determine the reliability of the different tests in a functional test battery. METHODS: Twenty-four male recreational athletes with unilateral functional ankle instability (FAI) were recruited for this study. One component of the test battery included five different functional ability tests. These tests included a single limb hopping course, single-legged and triple-legged hop for distance, and six and cross six meter hop for time. The ankle joint position sense and one leg standing test were used for evaluation of proprioception and sensorimotor control. The isokinetic strengths of the ankle invertor and evertor muscles were evaluated at a velocity of 120 degrees /s. The reliability of the test battery was assessed by calculating the intraclass correlation coefficient (ICC). Each subject was tested two times, with an interval of 3-5 days between the test sessions. RESULTS: The ICCs for ankle functional and proprioceptive ability showed high reliability (ICCs ranging from 0.94 to 0.98). Additionally, isokinetic ankle joint inversion and eversion strength measurements represented good to high reliability (ICCs between 0.82 and 0.98). CONCLUSION: The functional test battery investigated in this study proved to be a reliable tool for the assessment of athletes with functional ankle instability. Therefore, clinicians may obtain reliable information from the functional test battery during the assessment of ankle joint performance in patients with functional ankle instability.

Shoulder terminal range eccentric antagonist/concentric agonist strength ratios in overhead athletes.

OBJECTIVE: The agonist-antagonist strength relationship for shoulder external rotation and internal rotation was formerly described by the relatively more functional ratios of eccentric external rotator to concentric internal rotator moments, and eccentric internal rotator to concentric external rotator moments for the entire range of motion. The aim of this study was to provide descriptive data for terminal range eccentric antagonist/concentric agonist rotator cuff strength in overhead athletes. METHOD: The dominant and non-dominant shoulders of 40 asymptomatic military overhead athletes were tested through a range of 20 degrees of external rotation to 90 degrees of internal rotation using the Cybex NORM isokinetic dynamometer at a speed of 90 degrees /s. Differences between the dominant and non-dominant shoulders were assessed using the paired samples t-test. RESULTS: The terminal range ratios during external rotation (20 degrees of internal rotation - 10 degrees of external rotation) were found to be 2.09 and 1.58 for the dominant and non-dominant shoulders, respectively, whereas the terminal range ratios during internal rotation (60-90 degrees of internal rotation) were 1.03 and 1.19 for the dominant and non-dominant shoulders, respectively. These ratio differences between the dominant and non-dominant shoulders were significant (P<0.01 for external and internal rotation). CONCLUSION: The muscle torque ratios of eccentric antagonist/concentric agonist are different between dominant and non-dominant shoulders of skilled overhead athletes at terminal ranges. This functional assessment of strength testing that reflects dynamic shoulder joint stability during the throwing activity at these specific ranges may provide valuable information either during preventive exercise programs or in the evaluation of the injured shoulder of the overhead athlete. We recommended functional exercises that improve eccentric external rotation strength on the dominant shoulder during the rehabilitation and prevention programs in overhead athletes.

Chronic groin pain in an amateur soccer player.

Chronic groin pain is common in soccer players because of the biomechanics of kicking causing recurrent stress to the abdominal muscles, groin flexors, and adductor muscles. Myositis ossificans in adductor muscles is a rare cause of chronic groin pain in soccer players. Only two cases have been reported and the iliopsoas muscle was involved in both. This case report emphasises the importance of direct radiography for diagnosis in chronic groin pain and is a reminder that the development of myositis ossificans in the adductor muscles may be a cause.

Relation between isokinetic muscle strength and functional capacity in recreational athletes with chondromalacia patellae.

OBJECTIVES: To investigate the effects of isokinetic exercise on pain and functional test scores of recreational athletes with chondromalacia patellae (CMP) and to examine the correlation between isokinetic parameters and functional tests or pain score. METHODS: The functional ability of 30 recreational athletes with unilateral CMP was evaluated using six different tests. Pain scores were assessed during daily activities before and after the treatment protocol. Isokinetic exercise sessions were carried out at angular velocities of 60 degrees /s (25-90 degrees range of flexion) and 180 degrees /s (full range). These sessions were repeated three times a week for six weeks. RESULTS: Quadriceps and hamstring peak torque, total work, and endurance ratios had improved significantly after the treatment, as did the functional parameters and pain scores. There was a poor correlation between the extensor endurance ratio and one leg standing test. A moderate correlation between the visual analogue scale and the extensor endurance ratio or flexion endurance ratio was also found. CONCLUSIONS: The isokinetic exercise programme used in this study had a positive effect on muscle strength, pain score, and functional ability of knees with CMP. The improvement in the functional capacity did not correlate with the isokinetic parameters.