Ufuk Sekir

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°/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.

Efficacy of isokinetic exercise on joint position sense and muscle strength in patellofemoral pain syndrome.

Hazneci B, Yildiz Y, Sekir U, Aydin T, Kalyon TA: Efficacy of isokinetic exercise on joint position sense and muscle strength in patellofemoral pain syndrome. Am J Phys Med Rehabil 2005;84:521–527. Objective:The objective of this study was to demonstrate the impairment of knee joint position sense in individuals with patellofemoral pain syndrome and investigate the effects of isokinetic exercise on knee joint position sense and muscle strength. Design:A total of 24 male patients complaining of anterior knee pain caused by overexertion and 24 male healthy individuals without symptoms were included for this investigation. Isokinetic exercise protocol was carried out at angular velocities of 60 degrees/sec and 180 degrees/sec. These sessions were repeated three times per week and lasted for 6 wks. At the beginning and after 6 wks of knee passive joint position sense, quadriceps and hamstring muscle strength and pain assessments were performed. Results:After the isokinetic exercise, flexion peak torque (P < 0.05), extension peak torque (P < 0.01), flexion total work (P < 0.001), extension total work (P < 0.001), passive reproduction of knee joint position sense for 40 degrees of flexion (P < 0.05) and 50 degrees of extension (P < 0.01), and pain score (P < 0.001) improved significantly in the patellofemoral pain syndrome group. Conclusion:Isokinetic exercises have positive effects on passive position sense of knee joints, increasing the muscular strength and work capacity. These findings show that using the present isokinetic exercise in rehabilitation protocols of patients with patellofemoral pain syndrome not only improves the knee joint stabilization but also the proprioceptive acuity.

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.

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°/s (25–90° range of flexion) and 180°/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.

Early Versus Late Start of Isokinetic Hamstring-Strengthening Exercise After Anterior Cruciate Ligament Reconstruction With Patellar Tendon Graft

Backgound Hamstring strengthening after anterior cruciate ligament reconstruction is a vital component of the rehabilitation program. Purpose The objective of this trial was to investigate the effects of hamstring isokinetic training used in the early phase of the rehabilitation program on the stability, strength, symptoms, and functional outcomes of patients throughout 12 months after anterior cruciate ligament surgery. Study Design Randomized controlled clinical trial; Level of evidence, 2. Methods Forty-eight men underwent anterior cruciate ligament reconstruction with an ipsilateral bone—patellar tendon—bone autograft. The patients were randomly assigned to perform daily isokinetic hamstring exercises at postoperative 3 weeks (group I) or to perform daily isokinetic hamstring exercises at postoperative 9 weeks (group II). The patients were evaluated monthly for the first 4 months and at the 12th month for postoperative hamstring and quadriceps strength, as well as for knee function via the Cincinnati Knee Rating Scale and International Knee Documentation Committee form. Results Hamstring isometric strength at 30° of knee flexion (at the first and second months) and concentric isokinetic strength (at 2, 3, 4, and 12 months) at the angular velocity of 60 deg/s were significantly (P < .05-.01) greater in group I compared with group II. Average scores of the Cincinnati Knee Rating Scale for symptoms were significantly (P < .05-.001) higher in group I compared with group II at all evaluation periods. Walking and stair-climbing scores at 1, 2, 3, and 4 months and squatting score at all evaluation periods were also better (P < .05-.01) in group I compared with group II. In addition, group I exhibited better (P < .01-.001) Lachman test results compared with group II for all postoperative evaluation periods. The International Knee Documentation Committee final rating scores were significantly (P < .01) greater at 2, 3, and 4 months in group I compared with group II. Conclusion The results of this study suggest that hamstring as well as quadriceps strength can be increased via early hamstring strengthening after anterior cruciate ligament reconstruction with no negative impact on knee function.

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.

Eccentric Training Improves Ankle Evertor and Dorsiflexor Strength and Proprioception in Functionally Unstable Ankles.

ObjectiveThe aim of this study was to investigate the effects of a combined eccentric-concentric exercise program of the ankle evertors and dorsiflexors on proprioception in functionally unstable ankles. DesignThirteen male recreational athletes with unilateral functional ankle instability were admitted to this study. The unaffected opposite ankles were used as controls. The functionnaly unstable ankle of the subjects performed an isokinetic exercise program of the ankle evertors and dorsiflexors in a combined eccentric-concentric mode for 3 days per week for 6 wks. Before and after the isokinetic exercise program, active and passive joint position sense and kinesthesia and isokinetic strength of the ankle joint were evaluated. ResultsActive and passive joint position sense error scores for inversion (P < 0.01–0.001) and plantarflexion (P < 0.05–0.001) direction and kinesthesia scores for inversion (P < 0.001) and plantarlexion (P < 0.01) direction showed significant reductions after 6 wks of intervention in the functionnaly unstable ankle. In addition, eccentric peak torques for the ankle evertor and dorsiflexors represented significant (P < 0.001) increases in the functionnaly unstable ankle compared with the control ankle. ConclusionsThe results of this study suggest that it is possible to improve proprioceptive acuity of the ankle joint after a 6-wk eccentric-concentric isokinetic training program in functionally unstable ankles.

Acute effects of static stretching on peak and end-range hamstring-to-quadriceps functional ratios.

AIM To evaluate if static stretching influences peak and end-range functional hamstring-to-quadriceps (H/Q) strength ratios in elite women athletes. METHODS Eleven healthy female athletes in an elite competitive level participated to the study. All the participants fulfilled the static stretching or non-stretching (control) intervention protocol in a randomized design on different days. Two static unassisted stretching exercises, one in standing and one in sitting position, were used to stretch both the hamstring and quadriceps muscles during these protocols. The total time for the static stretching was 6 ± 1 min. The isokinetic peak torque measurements for the hamstring and quadriceps muscles in eccentric and concentric modes and the calculations for the functional H/Q strength ratios at angular velocities of 60°/s and 180°/s were made before (pre) and after (post) the control or stretching intervention. The strength measurements and functional strength ratio calculations were based during the entire- and end-range of knee extension. RESULTS The pre-test scores for quadriceps and hamstring peak torque and end range values were not significantly different between the groups (P > 0.05). Subsequently, although the control group did not exhibit significant changes in quadriceps and hamstring muscle strength (P > 0.05), static stretching decreased eccentric and concentric quadriceps muscle strength at both the 60°/s and 180°/s test speeds (P < 0.01). Similarly, static stretching also decreased eccentric and concentric hamstring muscle strength at both the 60°/s and 180°/s test speeds (P < 0.01). On the other hand, when the functional H/Q strength ratios were taken into consideration, the pre-intervention values were not significant different between the groups both during the entire and end range of knee extension (P > 0.05). Furthermore, the functional H/Q strength ratios exhibited no significant alterations during the entire and end ranges of knee extension both in the static stretching or the control intervention (P > 0.05). CONCLUSION According to our results, static stretching routine does not influence functional H/Q ratio. Athletes can confidently perform static stretching during their warm-up routines.

P-16 Arterial stiffness differences between aerobically and resistance trained turkish elite athletes

Objectives The purpose of this study was to evaluate whether arterial stiffness was different in aerobically trained elite athletes than in anaerobic/resistance trained elite athletes. The cohort comprised 36 healthy male volunteers, aged 17 to 32 years. All subjects were basketball players (n = 10), weight lifters (n = 11) or sedentary controls (n = 15). Methods The Pulse Trace System (Micro Medical Ltd., Rochester, UK) was used to record central and peripheral arterial stiffness. Echocardiographic images were taken by the use of a commercially available machine (Vivid 7 GE-Vingmed, Horten, Norway) with a 2.5 MHz transducer. Results Aortic elastic properties derived from echocardiographic measurements did not differ between the groups (p > 0.05). Pulse wave velocity measurements reflected significantly lower values both in the basketball players and weight lifters compared to controls (p < 0.001–0.05). No significant differences were found between the basketball players and weight lifters (p > 0.05). Conclusions Many studies found increased central arterial stiffness in athletes performing chronic resistance exercise when compared to aerobic exercise (Miyachi et al. 2004; Cortez-Cooper et al. 2005; Kawano et al. 2006). Our study did not show any increased arterial stiffness in weightlifters. On the contrary, we found reduced stiffness. The reduction was not statistically significant and it was lower compared to basketball players. The aortic stiffness index of weightlifters was the same as sedentary controls unlike basketball players. These results show that arterial stiffness may be affected independently from cardiac parameters as reported in literature. Moreover, this may be caused by aerobic exercise that is part of the training programme of weightlifters. Different from the existing knowledge, arterial stiffness of athletes that perform more resistance exercise such as weightlifters, improved significantly. Acknowledgements We would like to thank Erciyes University Scientific Research Project unit for their financial support for this study (TSA-08-467). References Miyachi M, Kawano H, Sugawara J, Takahashi K, Hayashi K, Yamazaki K, Tabata I, Tanaka H2004. Unfavourable effects of resistance training on central arterial compliance: a randomised intervention study. Circulation, 110:2858–63. Cortez-Cooper MY, DeVan AE, Anton MM, Farrar RP, Beckwith KA, Todd JS, Tanaka H2005. Effects of high intensity resistance training on arterial stiffness and wave reflection in women. Am J Hypertens, 18(7):930–4. Kawano H, Tanaka H, Miyachi M2006. Resistance training and arterial compliance: keeping the benefits while minimising the stiffening. Journal of Hypertension, 24(9):1753–9.

Arterial Stiffness Differences between Aerobically and Resistance Trained Turkish Elite Athletes

Abstract The purpose of this study was to evaluate whether arterial stiffness was different in aerobicallytrained elite athletes than in anaerobically or resistance trained elite athletes. The cohort comprised 36 healthymale volunteers, aged between 17 and 32 years. All subjects were basketball players (n=10), weightlifters (n=11) orsedentary controls (n=15). The Pulse Trace System (Micro Medical Ltd., Rochester, UK) was employed to recordcentral and peripheral arterial stiffness. Echocardiographic images were taken by the use of a commerciallyavailable machine (Vivid 7 GE-Vingmed, Horten, Norway) with a 2.5 MHz transducer. Aortic elastic propertiesderived from echocardiographic measurements did not differ between the groups (p<0.05). Pulse wave velocitymeasurements reflected significantly lower values in both the basketball players and weightlifters compared tocontrols (p<0.001-0.05). No significant difference was seen between the basketball players and weightlifters(p<0.05). Contrary to existing knowledge, arterial stiffness of athletes that perform more resistance exercise suchas weightlifters improved significantly and did not get worse. This result implies that in the long-term arterialstiffness improves with sports activities that are predominantly comprised of resistance exercises despite increasedarterial stiffness in the acute phase.