Isokinetics and Exercise Science - Volume 19, issue 3

Authors: Bohannon, Richard W.

Article Type: Research Article

Abstract: This review was conducted to identify, summarize, and discuss literature purporting to present normative data for measurements obtained using a hand-held dynamometer (HHD). Relevant literature was identified through electronic searches of 4 databases: PubMed, Science Citation Index, Scopus and Cumulative Index of Nursing and Allied Health. Articles identified via the searches were reviewed to determine if they presented normative data obtained with a HHD from healthy individuals. Articles were excluded if the data were …not presented within age and gender strata. Data on testing and participant specifics were retrieved. Fifteen studies presented normative data within age and gender strata for measurements obtained with a HHD. Norms were presented for neck flexion and numerous actions at the shoulder, elbow, wrist, fingers, hip, knee and ankle. Norms were presented for a wide age span- children to older adults. Many of these norms are compromised. Norms for older adults (⩾ 80 years) are lacking. Although norms are available, they should be used with caution. Specifics of testing and samples tested restrict the applicability of the measures. Show more

Keywords: Muscle strength, measurement, dynamometry

DOI: 10.3233/IES-2011-0415

Citation: Isokinetics and Exercise Science, vol. 19, no. 3, pp. 143-147, 2011

Authors: Aktas, Gulcan | Baltaci, Gul

Article Type: Research Article

Abstract: Context: Knee injuries which are the most common disabling injuries in both athletic and physically active people, can be expected to occur with all sporting activities especially contact sports. Therefore, knee braces and taping techniques are widely used to reduce and/or prevent the severity and incidence of knee injuries in sports. Objective: To determine which application, knee brace, kinesiotaping (KT) or both, is more effective regarding muscular strength and functional performance. Design: …A prospective, criterion-based controlled study. Setting: University research laboratory. Patients or other participants: Twenty (11 F, 9M) healthy subjects with no previous history of lower extremity injuries and using knee brace and KT were included in this study. Main outcome measures: Muscular strength, and jump performance were tested with knee brace, kinesiotaping and both applications. Repeated measures ANOVA was performed to determine if there were differences between braced, taped and both conditions. Participants filled in a questionnaire regarding demographic and lower extremity problems. Results: Kinesiotape application brought about a significant increase in hop distance (p=0.015, P=0.018) in both the dominant and non-dominant extremity and in isokinetic knee extension peak torque (p=0.034) at 180°/s. Conclusion: KT application was more effective in terms of muscular strength and jump performance than knee brace and KT plus knee brace. Physical therapists and athletic trainers may apply KT to a patient during or after treatment and rehabilitation to support knee musculature, to encourage the tissue healing process, and to avoid limiting the enhancement of improved knee muscle performance. Show more

Keywords: Knee, strength, kinesio taping, brace, prophylactic

DOI: 10.3233/IES-2011-0408

Citation: Isokinetics and Exercise Science, vol. 19, no. 3, pp. 149-155, 2011

Authors: Sobolewski, Eric J. | Wagner, Dale R. | Bressel, Eadric

Article Type: Research Article

Abstract: The purpose of this study was to determine whether static stretching alone or combined with a warm-up affected isokinetic peak torque (IPT) of the quadriceps at both slow and fast velocities. Twenty physically active males (22.1 ± 2.4 years) performed maximal knee extensions under four conditions: no stretch control, stretch only, 5 min jog followed by stretches, and stretching followed by a 5 min jog. Total stretching volume was 360 s. A Biodex System 3 isokinetic …dynamometer was used to measure IPT at 60 and 300°/s. A 2 × 4 repeated measures ANOVA revealed that IPT was significantly different among the four test conditions (F=3.09, p=0.03) and follow-up comparisons revealed that the mean IPT of the stretching trial was 9.9 N·m less than the control trial (Effect size =0.19–0.42). Neither of the warm-up conditions combined with stretching were significantly different from the control. It was concluded that stretching affects IPT to a similar extent at both velocities tested, and that jogging done either prior to or after stretching does not appreciably alter knee extension IPT. The lower IPT following static stretching precludes recommending this activity prior to a maximal effort. Show more

Keywords: Force, strength, flexibility, quadriceps

DOI: 10.3233/IES-2011-0409

Citation: Isokinetics and Exercise Science, vol. 19, no. 3, pp. 157-162, 2011

Authors: Wang, Ying-Chih | Bohannon, Richard W. | Magasi, Susan R. | Hrynkiewicz, Beata | Morales, Aaron | Gershon, Richard C. | Rymer, Zev

Article Type: Research Article

Abstract: Given the functional and epidemiological significance of lower extremity strength, portable, low-cost measures of lower extremity strength with robust psychometric properties are needed for clinical practice and research. The purpose of this study was to compare measures of isometric knee extension strength obtained with portable devices with criterion measures obtained with a Biodex dynamometer. Sixty-eight healthy adults from Illinois and Connecticut participated in this study. Each participant's isometric knee extension strength was …tested in random order using: 1) an integrated tension load cell device (ITLCD), 2) a belt stabilized hand held dynamometer (BSHHD) and 3) a Biodex System 3 isokinetic dynamometer. Equivalence of the 3 measures was evaluated using repeated measures analysis of variance (ANOVA), Pearson correlations (r), and intraclass correlation coefficients (ICCs). Results supported good agreement between measures obtained with the ITLCD, BSHHD and Biodex (r > 0.90, ICCs > 0.79). The ANOVA results demonstrated that measures obtained with the ITLCD and the BSHHD did not differ significantly. On average, the maximum isometric knee extension torque was underestimated by 27 N-m and 32 N-m by the ITLCD and BSHHD, respectively. Because The ITLCD was slightly better at approximating Biodex torque scores and does not depend on skills of the examiner, the ITLCD was recommended for inclusion in the motor battery of the NIH Toolbox. Show more

Keywords: Isometric dynamometry, measurement, muscle strength

DOI: 10.3233/IES-2011-0410

Citation: Isokinetics and Exercise Science, vol. 19, no. 3, pp. 163-168, 2011

Authors: Van Tiggelen, D. | Coorevits, P. | Bernard, E. | Thijs, Y. | Witvrouw, E.

Article Type: Research Article

Abstract: Background: Previous studies have indicated that wearing a patellofemoral brace during strenuous training resulted in a decreased incidence of anterior knee pain (AKP). However whether this effect is derived from quadriceps enhancement remains unknown. Study design: Randomized controlled clinical trial. Methods: Ninety-eight military recruits, 35 'with-brace' and 63 without, underwent concentric isokinetic tests at 60 and 240°/s of the quadriceps prior to and following a 6-week basic military training (BMT). The randomly …selected 35 subjects 'with brace' received a pair of patellofemoral braces (On-Track, DJ Ortho) and were instructed to wear these braces throughout training. Results: Baseline strength characteristics of the quadriceps were not significantly different between the braced and non-braced group (p > 0.05). No significant time-effect was observed in the braced group. There was a significant decrease in quadriceps strength at 60°/s after BMT in the non-braced subjects (p < 0.001) while at this speed these subjects had a significantly (p =0.02) lower strength compared to their non-braced counterparts. Conclusion: Patellofemoral bracing may be effective in preventing a decrease in quadriceps strength after prolonged strenuous training. Show more

Keywords: Bracing, anterior knee pain, quadriceps

DOI: 10.3233/IES-2011-0411

Citation: Isokinetics and Exercise Science, vol. 19, no. 3, pp. 169-173, 2011

Authors: da Silva, Rubens A. | Larivière, Christian | Plamondon, André | Arsenault, A. Bertrand | Nadeau, Sylvie

Article Type: Research Article

Abstract: The purpose of this study was to examine the effect of pelvic stabilization and lower-limb configuration on trunk extension strength and to test whether sex modify these effects. Twenty-two healthy volunteers (11 women and 11 men: SEX factor), age range 20–55 years participated in this study. Two isometric maximal voluntary contractions (MVCs) were performed in extension and the moment was calculated relative to L5/S1, for each of six experimental conditions. Two different positions were tested (POSITION …factor): I) seated position (knees at 90°) and II) semi-sitting position (knees at 45°). In each POSITION, three pelvic stabilization conditions were tested (STABILIZATION factor): (1) unrestrained (control condition), (2) partially restrained (posteriorly) and (3) totally restrained (posteriorly and anteriorly). No significant main effects (p> 0.05) and no double and triple (SEX × STABILIZATION × POSITION) interaction reached statistical significance. Consequently, maximal trunk extension moment can be achieved with the use of various stabilization and positioning modalities, at least when the same apparatus allows such flexibility, and this as much in women as in men subjects. These results have implications for the assessment of trunk extension strength during pre- and post-training regiments during a rehabilitation program for strengthening of back muscles in patients with low back pain. Show more

Keywords: Back muscles, strength, rehabilitation, training, stabilization, position

DOI: 10.3233/IES-2011-0412

Citation: Isokinetics and Exercise Science, vol. 19, no. 3, pp. 175-179, 2011

Authors: Cerrah, Ali Onur | Gungor, Elvin Onarıcı | Soylu, Abdullah Ruhi | Ertan, Hayri | Lees, Adrian | Bayrak, Coşkun

Article Type: Research Article

Abstract: The aim of the study was to define activation characteristics of knee muscles of the kicking leg during the in-step kick and interpret these in relation to isokinetic strength parameters and ball velocity in professional (N=14) compared to amateur (N=17) soccer players. Electromyographic (EMG) recordings were taken from the rectus femoris (RF), vastus lateralis (VL), vastus medialis (VM), long head of biceps femoris (BF) and medial gastrocnemius (GAS) as players performed three …successful maximal in-step kicks using a 0° approach angle with two steps to a stationary ball towards a target. Kicks were also recorded with high speed video and ball velocity was measured by a radar gun. Afterward the bilateral concentric isokinetic strength of the knee extensors and flexors was recorded. Results suggest that during the swing phase, BF activation occurred significantly earlier, RF showed reduced activation and an earlier and greater muscle activity occurred in VL and VM in professionals compared to amateur players. During knee extension, VL and VM showed a markedly greater magnitude of muscle activity in professionals; during the follow through, GAS showed reduced activity in professionals. Relationships between muscle strength and performance (ball speed) were found for amateurs but not for professionals (r=0.57 to r=0.72, p< 0.05). The findings of this study indicate that the superior performance of professional players compared to amateurs appears not to be due to muscle strength factors but rather to subtle differences in technique, as indicated by EMG data, throughout both the build up and execution of the kick. Show more

Keywords: Electromyography, kicking leg, peak torque, ball speed

DOI: 10.3233/IES-2011-0414

Citation: Isokinetics and Exercise Science, vol. 19, no. 3, pp. 181-190, 2011

Authors: do Carmo, Filipe C. | Pereira, Rafael | Machado, Marco

Article Type: Research Article

Abstract: The aim of this study was to assess how much risk a resistance exercise can provide to individuals who have distinguished hyperCKemia response. Twenty-three healthy men performed an exercise protocol, during which 4 sets of biceps curl were performed at 85% of 1 repetition maximum (1RM). Each bout was performed to voluntary fatigue and the workout volume completed was calculated. Subjects provided blood samples prior, and at 24, and 48 h following exercise to evaluate serum …creatine kinase (CK) activity. Based on serum CK activity responses the subjects were separated into two groups called: Normal Responders (NR) or High Responders (HR). A great interindividual variability in serum CK activity following exercise and a significant difference between NR and HR were observed. The workout volume demonstrated a significant reduction along sets but without difference between NR and HR. Our main finding was the great inter-individual variability in serum CK activity that is seen even when using a single exercise performed on a the day-to-day basis. Show more

Keywords: Exercise, muscle damage, muscular stress, biochemical markers, creatine kinase

DOI: 10.3233/IES-2011-0416

Citation: Isokinetics and Exercise Science, vol. 19, no. 3, pp. 191-197, 2011

Authors: Meamarbashi, Abbas | Abedini, Farhad

Article Type: Research Article

Abstract: Purslane is the richest vegetable source of omega-3 fatty acids and antioxidant nutrients. This is the first attempt to elucidate the possible effects of Purslane extract on muscle soreness. To examine the preventive effects of Purslane extract on delayed muscle soreness (DOMS) following one session eccentric exercise, twenty healthy non-athlete students were randomly assigned to the experimental and control groups. Experimental group received Purslane extract (n=10), 1200 mg/day from 72 hours before …training until 48 hours after training. One session bench-stepping exercise performed to induce DOMS. Serum LDH, CK, Cortisol, IgA, Sodium and Potassium, maximal knee extension isometric force, thigh circumference, knee range of motion, and pain perception were measured 72 hours before exercise, immediately post, 24 and 48 hours after exercise. Serum concentration of LDH and Cortisol in 24 and 48 h after exercise exhibited a significant difference between control and experimental groups (P< 0.05). Serum CK was significantly lower after 48 h (P< 0.001). IgA has shown lower concentration immediately post, 24 and 48 h after exercise (P< 0.01). The level of pain perception was significantly lower in experimental group after 48 hours (P< 0.005). The right knee range of motion and maximal isometric force were significantly lower in the experimental group after 48 h (P ⩽ 0.05). These findings suggest that Purslane extracts reduced the biochemical and clinical variables of DOMS and it can be speculated that Purslane extracts is effective in prevention of DOMS. Show more

Keywords: Portulaca oleracea, prevention, muscle soreness, eccentric exercise

DOI: 10.3233/IES-2011-0417

Citation: Isokinetics and Exercise Science, vol. 19, no. 3, pp. 199-206, 2011

Authors: Huber, Juliusz | Lisiński, Przemysław | Samborski, Włodzimierz | Wytrążek, Marcin

Article Type: Research Article

Abstract: Objective: To determine the effects of early introduction of isometric exercises on pain intensity and trunk and lower extremity muscles strength in patients with sciatica. Methods: Fifty two patients treated for disc herniation with sciatica were included in this randomized controlled single-blinded study. They were examined twice, before and after twenty days of rehabilitation, with neuroimaging, visual analog scale (VAS), straight leg rising test (SLR), range of spine movement in a saggital plane, muscle …strength, electromyography (EMG), electroneurography (ENG) and intensity of current vs stimulus duration tests (IC-SD). Twenty-six patients, selected randomly, were ordered to reduce the physical activity and frequent loading of the spine (conventional [C] group) while 26 patients underwent a program of supervised isometric exercises (intervention [I] group). A control group of healthy subjects performed once the same examination. Results: Following treatment the muscle strength and flexibility of the spine showed significant (P< 0.05) improvement in I group with a significantly lower pain level and number of positive SLR tests. The same tests performed in C group indicated no parallel improvement. EMG Parameters increased in almost all muscles, but only in the I group were they associated with simultaneous improvement in ENG examinations of peroneal nerves. Conclusion: Early introduction of isometric exercises, 14 days after the incidence, is a relevant choice in cases of patients with sciatica caused by the disc herniation. Show more

Keywords: Sciatica, isometric exercises, strengthening, early rehabilitation, clinical and neurophysiological evaluation

DOI: 10.3233/IES-2011-0418

Citation: Isokinetics and Exercise Science, vol. 19, no. 3, pp. 207-214, 2011

Authors: Baroni, Bruno Manfredini | Stocchero, Cíntia Mussi Alvim | do Espírito Santo, Rafaela Cavalheiro | Ritzel, Cíntia Helena | Vaz, Marco Aurélio

Article Type: Research Article

Abstract: This study investigated knee extensor muscle strength, work and fatigue level under maximal isokinetic concentric and eccentric exercise. Seventeen male athletes were randomized into two groups and performed 10 sets of 10 maximal isokinetic concentric (N =8) or eccentric (N =9) contractions. Knee extensor peak torque and mean torque values per set were 54–121% and 53–133% higher in eccentric compared to concentric exercise, respectively, whereas the percent fall of performance in these …variables was more accentuated in concentric exercise. Total work was significantly higher in eccentric exercise (19475 J) than concentric exercise (15758 J), while fatigue index was greater in concentric (36%) than eccentric (18%) exercise. In conclusion, maximal isokinetic eccentric exercise promotes larger overload to knee extensor muscles than its concentric counterpart due to higher torque produced by the muscle group and also thanks to minor muscle fatigue effects. Show more

Keywords: Knee extensors, concentric exercise, eccentric exercise, task-dependency

DOI: 10.3233/IES-2011-0421

Citation: Isokinetics and Exercise Science, vol. 19, no. 3, pp. 215-220, 2011

Authors: dos Santos Rocha, Clarice Sperotto | Baroni, Bruno Manfredini | Lanferdini, Fábio Juner | de la Rocha Freitas, Cíntia | Frasson, Viviane Bortoluzzi | Vaz, Marco Aurélio

Article Type: Research Article

Abstract: Although previous studies have demonstrated that skeletal muscle adaptations were specific to the types of stimuli, eccentric training studies presented controversial results concerning strength gains in eccentric, isometric and concentric tests. Therefore, the goal of this study was to evaluate torque-velocity adaptations following isokinetic eccentric training protocol using the quadriceps as a model. Twenty physically active men were randomly assigned to a control group (CG; n=10) or to an eccentric training group …(ETG; n=10). Knee extensor torque-velocity relationship including isometric tests and isokinetic tests at 60°/s, 120°/s, 180°/s, 240°/s and 300°/s in concentric and eccentric modes, were assessed before and after a 12-week period of eccentric training (3 sessions/week; 2–5 sets of 7–9 maximal repetitions per session performed at 60°/s along a range of motion 90°). Isokinetic eccentric training significantly increased the knee extensor torque at the training velocity (59%) and at the adjacent velocities (24% at 120°/s and 29% in the isometric test). These results demonstrate the specificity of strength gains in isokinetic eccentric training in relation to contraction type and to angular velocity. Show more

Keywords: Eccentric exercise, muscle adaptation, knee extensor, torque-velocity relationship

DOI: 10.3233/IES-2011-0425

Citation: Isokinetics and Exercise Science, vol. 19, no. 3, pp. 221-226, 2011

Authors: Patlar, Suleyman

Article Type: Research Article

Abstract: This study aimed to examine effects of acute and chronic submaximal exercise on plasma renin and aldosterone levels in football players. Seven apparently healthy, male footballer subjects took part in the study. The subjects were exercised on ergometric bicycles for 20-min at 75% of Max VO_{2} , 3 days a week for 4 weeks. Blood samples were collected on 4 occasions: before the exercise, immediately after the exercise, as well as 2 hours and 24 hours after …the exercise. Plasma renin and aldosterone levels (RIA) were measured. Exercise significantly increased plasma renin and aldosterone levels of the athletes before and after the exercise (p < 0.05). The levels at the 2nd hour following exercise dropped significantly in comparison to those immediately after the exercise (p< 0.05). Plasma values one day after the exercise were significantly lower than those after the 2nd hour (p < 0.05). Consequently, acute and 4-week chronic submaximal exercise have significant effects on plasma renin and aldosterone levels in football players (p< 0.05). Show more

Keywords: Submaximal exercise, renin, aldosterone

DOI: 10.3233/IES-2011-0428

Citation: Isokinetics and Exercise Science, vol. 19, no. 3, pp. 227-230, 2011