Isokinetics and Exercise Science - Volume 16, issue 2

Authors: Tsiganos, G. | Kalamvoki, E. | Smirniotis, J.

Article Type: Research Article

Abstract: Purpose: to determine whether subjects with chronic ankle instability (CAI) suffer proprioceptive deficits (joint position sense) in the proximal joint (knee) of the injured ankle. Methods: Fourteen subjects with unilateral CAI and 14 healthy controls participated in this study. We tested knee joint position sense using an isokinetic dynamometer. Knee joint position testing was carried out at 30°, 45° and 70° knee flexion. The difference between perceived angle and actual angle was …recorded as the error. Results: Mean value of error was statistically significant in subjects with CAI compared with control subjects (30° p< 0.001, 45° p< 0.023 and 70° p< 0.050). Mean error value at 30° was also statistically greater than mean error value at 70° (p< 0.015). Conclusions: Changes in knee joint position sense in subjects with CAI suggest further emphasis on assessment of the joint proximal to the level of injury and subsequent planning of a rehabilitation program. Further research is required to determine the exact contributions to knee joint proprioception. Show more

Keywords: Proprioception, ankle sprain, knee, joint position sense

DOI: 10.3233/IES-2008-0299

Citation: Isokinetics and Exercise Science, vol. 16, no. 2, pp. 75-79, 2008

Authors: Tansel, Rifat Baran | Salci, Yasar | Yildirim, Ahmet | Kocak, Settar | Korkusuz, Feza

Article Type: Research Article

Abstract: Objective: To investigate the effects of eccentric hamstring training on strength measures and vertical jumping performance. Methods: 26 male basketball players aged 10–12 were divided into Nordic Hamstring Strength Training group (N=15) and control group (N=11). Training was conducted over a 5-week period during which both groups participated in basketball training. All participants underwent pre- and post-training testing comprising isokinetic concentric and eccentric knee extension and flexion strength and vertical …jump performance. Results: The NHST group exhibited significant increase in eccentric hamstring strength (p< 0.05) and vertical jumping ability (p< 0.01) whereas the performance of the control group remained unchanged during that period. Conclusion: Including eccentric exercises into entire training program improve muscular strength and can help athletes to reach their highest potential so they produce greater muscular forces. Show more

Keywords: Hamstring, eccentric training, vertical jump

DOI: 10.3233/IES-2008-0300

Citation: Isokinetics and Exercise Science, vol. 16, no. 2, pp. 81-85, 2008

Authors: Kin-İsler, Ayse | Ariburun, Bayrak | Ozkan, Ali | Aytar, Aydan | Tandogan, Reha

Article Type: Research Article

Abstract: The purpose of this study was to investigate the relationship between, isokinetic knee strength, anaerobic performance and sprinting ability in American football players. Twenty-eight male amateur American football players participated in this study voluntarily. Knee extension and flexion strengths were evaluated at 60, 150 and 240°/s, anaerobic performance was evaluated by Wingate anaerobic power test and sprint ability was determined by single- (20 m) and repeated-sprint (12 × 20 m) tests. Extension strength …was significantly correlated with peak and mean power in all contraction velocities; however the only significant correlation between flexion strength and peak power was indicated at 240°/s. In the case of sprinting ability, there was a significant but weak correlation between 240°.s^{-1} knee flexion strength and percentage of performance decrement from 10–20 m (r=0.381, p< 0.05). No measure of strength was significantly related to single-sprint and other measures of repeated-sprint ability (p> 0.05). Hence, although maximal knee extension strength is a crucial component in anaerobic performance of American football players, lack of its association with single- and repeated-sprint performance indicates that factors other than strength might be involved in single-and repeated-sprint performance in this group of athletes. Show more

Keywords: Isokinetic strength, anaerobic power, anaerobic capacity, sprinting

DOI: 10.3233/IES-2008-0301

Citation: Isokinetics and Exercise Science, vol. 16, no. 2, pp. 87-92, 2008

Authors: Camargo, Paula R. | Haik, Melina N. | Filho, Raul B. | Mattiello-Rosa, Stela M.G. | Salvini, Tania F.

Article Type: Research Article

Abstract: Objective: To evaluate muscle contraction parameters during scaption of the shoulder in patients with subacromial impingement syndrome (SIS). Method: Thirty-three male subjects were evaluated. The impingement group consisted of 17 assembly line workers (31.6 ± 6.4 years) with unilateral SIS. The control group consisted of 16 healthy and active subjects (29.5 ± 6.2 years). Acceleration time, time to peak torque, peak torque, total work and power were measured bilaterally during isokinetic concentric scaption, at 60°/s …and 180°/s. Results: None of the isokinetic parameters differed bilaterally in the SIS group but compared to the control group showed impaired muscle activity in all parameters at both speeds (P < 0.05). Conclusions: Muscle contraction parameters are altered in both involved and uninvolved shoulders during scaption in patients with SIS. Show more

Keywords: Subacromial impingement syndrome, isokinetics, testing

DOI: 10.3233/IES-2008-0302

Citation: Isokinetics and Exercise Science, vol. 16, no. 2, pp. 93-99, 2008

Authors: Lin, Yang Hua | Li, Chen Wei | Tsai, Li Ying | Liing, Rong-Jiuan

Article Type: Research Article

Abstract: Objective: To investigate whether muscle fatigue of ankle invertors and evertors reduces the ability to detect inversion and eversion angles in subjects with an ankle proprioceptive deficit. Design: A cross-sectional before-after study with repeated measures design. Setting: Research laboratory. Subjects: Thirty young adults with defective passive joint sense of ankle inversion were recruited into this study and compared with 30 similar controls without ankle proprioceptive deficits. Interventions: …Muscle fatigue of ankle invertors and evertors was defined as occuring when the maximal isokinetic torque declined to below 50% of the peak torque. Main measures: The absolute differences between the angles detected and assigned, with target angles at inversion 10°, inversion 20°, and eversion 10° trialled in random orders. Results: Proprioceptive deficits and muscle fatigue of ankle inversion and eversion had a significant interaction with the ability to detect small amplitude target angles. Detecting 10° of ankle eversion and inversion showed significantly greater errors than for 20° of ankle inversion. Following muscle fatigue or in subjects with proprioceptive deficits there were greater errors in detecting small amplitudes of ankle positions (10° of ankle inversion and eversion). Conclusions: The potential deleterious effects of fatigue and proprioceptive deficits on the ability to detect the small range of lateral movements of ankle joint was addressed in this investigation.. Fatigue worsens chronic proprioceptive ankle deficits and hence may enhance the risk of injury. Show more

Keywords: Ankle injury, muscle fatigue, position sense, proprioceptive deficits

DOI: 10.3233/IES-2008-0303

Citation: Isokinetics and Exercise Science, vol. 16, no. 2, pp. 101-105, 2008

Authors: Bohannon, Richard W. | Vigneault, Jeremy | Rizzo, Jon

Article Type: Research Article

Abstract: Little research has focused on the measurement of both hip external and internal rotation strength. The purpose of this study was to describe the consistency of isometric hip rotation forces measured by hand-held dyanamometry. Specifically, we described the consistency over time and between sides. For 15 subjects measured during 2 sessions one week apart, rotation forces and force ratios did not differ significantly. Intraclass correlation coefficients (ICCs) were high (0.836–0.944) except for the external to …internal rotation force ratio on the right side (0.367). For 32 subjects measured during 1 session, hip external rotation forces and rotation force ratios did, but hip internal rotation forces did not, differ between sides. The between-side ICCs were high for the force measures (0.897&0.901) but not for the force ratio (0.337). Unlike force ratios, isometric force measurements obtained during a previous test session or from the other side provide a basis for measurement interpretation. The method errors and coefficients of variation of the method error that we report may be helpful in such interpretation. Show more

Keywords: Muscle strength, measurement, hip, reliability

DOI: 10.3233/IES-2008-0304

Citation: Isokinetics and Exercise Science, vol. 16, no. 2, pp. 107-111, 2008

Authors: Yuzer, Serdil | Aydog, Ece | Gurcay, Eda | Unlu, Ece | Cakci, Aytul

Article Type: Research Article

Abstract: Objectives: To determine the intra-rater reproducibility of normalized lifting strength (NLS) measurements. Methods: 30 healthy male volunteers with a mean age of 28.16 ± 7.59 years participated in this study. Each subject was tested by the same physician twice in a week, with at least 48 hours between the test sessions. For the evaluation of intra-rater reproducibility, intraclass correlation coefficients (ICC), the standard error of measurement (SEM) and the smallest real difference (SRD) and Bland …and Altman method were used. Results: Intra-rater ICCs of the NLS were 0.77 and 0.67 at 19.4 and 38.9 cm/s, respectively. The SEM% were 13.2% and 20.1% while the SRD% were 36.6% and 55.8% at these velocities, respectively. Conclusions: The reproducibility of NLS using the Biodex Lift Simulation Attachment was moderate in terms of the ICC and low in terms of the SRD. Thus the test, as described and applied is not sufficiently sensitive to detect clinically relevant changes. Show more

Keywords: Lifting strength, isokinetics, reproducibility, test-retest

DOI: 10.3233/IES-2008-0305

Citation: Isokinetics and Exercise Science, vol. 16, no. 2, pp. 113-118, 2008

Authors: Hesar, N. Ghani Zadeh | Calders, P. | Thijs, Y. | Roosen, P. | Witvrouw, E.

Article Type: Research Article

Abstract: The purpose of this study was to investigate the effect of the three phases (menstrual, follicular, luteal phase) of the menstrual cycle on active and passive ankle joint position sense. Twenty five healthy women with regular menstrual cycle, not pregnant and no contraceptive using with normal and consistent length of menstrual cycle and bleeding days participated in the study. Blood samples were collected from each subject for determination of hormonal level the phases of menstrual cycle. …Ankle joint position sense changes during three different phases of the menstrual cycle were assessed. Active and passive joint position sense of dominant leg of subjects was measured using the Biodex 2 isokinetic dynamometer. The absolute reposition errors from the target angles have been evaluated by repeated measure analysis of variance (ANOVA) in three hormonally verified phases of menstrual cycle. No significant interaction was observed between ankle joint position sense test and the phases of the menstrual cycle. We did not identify ankle joint position sense alteration across the menstrual, follicular and luteal phases. We suggest that the menstrual cycle does not significantly affect ankle joint position sense. Show more

Keywords: Menstrual cycle, proprioception, joint position sense, ankle

DOI: 10.3233/IES-2008-0306

Citation: Isokinetics and Exercise Science, vol. 16, no. 2, pp. 119-123, 2008

Authors: Thomas, Elin Magnusson | Sahlberg, Margareta | Svantesson, Ulla

Article Type: Research Article

Abstract: Handgrip strength is used to evaluate hand function. Handgrip strength may be used to assess generalized upper extremity strength and activities of daily living. This study aimed to evaluate the effect of general resistance training of the upper extremities on handgrip strength and to present hand-grip strength values, measured with the Grippit®, for young adult subjects in Sweden. Forty one healthy subjects, 27 women and 14 men, volunteered to participate in the …study. The women's group were randomly split between a training group (TG; n=15) and a control group (CG; n=12). Training consisted of general resistance for the upper extremities three times a week for 8 weeks. Values outcome measures included maximal voluntary contraction (MVC) and sustained MVC (SMVC). A significant difference (p<0.001) in strength was found between the right and the left hand (8–11% when accounting for right hand dominance. The TG showed significantly higher (p<0.05) MVC for the right hand after training. It appears that handgrip strength may be increased by eight weeks of general resistance training for the upper extremities. The findings in this study support the 10% rule for a population that is right-handed. Show more

Keywords: Grip force evaluation, upper extremity strength, resistance training

DOI: 10.3233/IES-2008-0307

Citation: Isokinetics and Exercise Science, vol. 16, no. 2, pp. 125-131, 2008

Authors: Tornese, Davide | Bandi, Marco | Volpi, Piero | Schonhuber, Herbert | Denti, Matteo | Ricci, Gabriele | Melegati, Gianluca

Article Type: Research Article

Abstract: Objective: to compare the outcomes of arthroscopic reconstruction of the posterior cruciate ligament (PCL) by means of the double bundle technique with the ipsilateral semitendinosus and gracilis (St-Gr) and the single bundle technique with the ipsilateral patellar tendon (PT). Methods and measures: 14 patients had randomly been assigned to either PT ot St-Gr graft for PCL reconstruction. The IKDC Knee Ligament Evaluation Form, the Lysholm Knee Scoring Scale, the Cincinnati Knee Rating Scale and …concentric isokinetic knee extensor-flexor test at 60 and 180°/s were used to compare the results. Results: there were no significant differences in the clinical scores. The isokinetic tests, however, disclosed a significant loss of strength at the harvest site. Conclusion: since biomechanical considerations underscore the importance of recovery of the quadriceps after PCL reconstruction, employment of the semitendinous and gracilis with a possible loss of flexor strength could be rationally more acceptable solution than reconstruction with the patellar tendon and weakening of the extensors. Show more

Keywords: Posterior cruciate ligament reconstruction, rehabilitation, isokinetics

DOI: 10.3233/IES-2008-0308

Citation: Isokinetics and Exercise Science, vol. 16, no. 2, pp. 133-137, 2008

Authors: Croce, R.V. | Miller, J.P. | Horvat, M.

Article Type: Research Article

Abstract: Examining the effects of fatigue on hamstrings' functioning can provide useful information regarding their role in stabilizing the knee joint. The purpose of the present investigation was to determine the effect of fatiguing, maximum effort, reciprocal isokinetic flexion-extension movements on peak torque (PT) and average torque (AVT) of the knee flexors and extensors, and agonist and antagonist medial hamstrings (MH) and biceps femoris (BF) surface electromyography (SEMG), as measured by the root mean square amplitude …(RMS) and median frequency of the frequency spectrum (MDF). Ten healthy adult female university students (age=22.5 ± 2.0 years) performed 32 maximal effort contractions of the quadriceps (extension) followed by maximal effort contractions of the hamstrings (flexion) at an angular velocity of 400°· s^{-1} . Data were normalized (as a percentage) and compared to maximum voluntary contractions (MVC) at repetitions 8, 16, 24, and 32. Separate repeated measures analyses of variance were performed on data to determine changes from MVC levels. Results indicated: (1) there were significant declines in PT and AVT from MVC levels across repetitions tested; (2) when acting as agonists MH and BF displayed increased RMS across repetitions tested, except from repetition 8-to-16; (3) when acting as antagonists MH and BF displayed no significant differences in RMS across repetitions tested; and, (4) there was a steady decline in MDF across repetitions tested in both MH and BF muscles when acting as agonists and antagonists, indicating a shift in motor unit recruitment from fast-to-slow twitch units. Based on the results, it appears that the MH and BF behave in unison when acting as either agonists or antagonists but as a muscle pair, they behave differently when acting in agonist or antagonist mode. As agonists, the MH and BF displayed increased amplitude and decreased spectral frequency over the course of a fatiguing, maximum effort, reciprocal isokinetic flexion-extension test performed at 400°·s^{-1} . However, when acting as antagonists, they displayed stable amplitude with decreasing spectral frequency. Show more

DOI: 10.3233/IES-2008-0309

Citation: Isokinetics and Exercise Science, vol. 16, no. 2, pp. 139-149, 2008