Isokinetics and Exercise Science - Volume 24, issue 3

Authors: Northgraves, Matthew J. | Hayes, Stephen C. | Marshall, Philip | Madden, Leigh A. | Vince, Rebecca V.

Article Type: Research Article

Abstract: BACKGROUND: Simple field tests are often used to assess functional mobility in clinical settings. Despite having many benefits, these tests are susceptible to measurement error and individual variation. OBJECTIVES: To examine the test-retest and absolute reliability of timed up and go test (TUG), five times sit-to-stand (FTSTS), stair climb test (SCT) and 6 minute walk (6MWT). METHODS: Over two sessions, thirty-five subjects (30-74 years), repeated the five tests approximately four weeks apart. Test-retest reliability (intraclass correlations [ICC]) and absolute reliability (95% limit of agreements [95% LOA]; standard error of measurement [SEM] and minimum …detectable change [MDC]) were calculated. RESULTS: All five tests had high test-retest reliability (ICC > 0.95) although significant between session changes were present for the TUG and FTSTS (p < 0.05). FTSTS displayed the greatest measurement error whilst 95% LOA was the most conservative measure of absolute reliability. CONCLUSIONS: The results of this study indicate that the TUG, FTSTS, SCT and 6MWT are reliable when performed four weeks apart. Furthermore, the inclusion of SEM, MDC and 95% LOA provides reference values to aid in identifying changes over time above those of measurement error and individual variation. Show more

Keywords: TUG, FTSTS, stair climb, 6MWT

DOI: 10.3233/IES-160614

Citation: Isokinetics and Exercise Science, vol. 24, no. 3, pp. 171-179, 2016

Authors: Martin, J.L. | Perry, R.A. | Baptista, R.A. | McArtor, J.D. | Clutter, L.B. | Symons, T.B. | de Paleville, D. Terson | Roberts, A. | Cesarz, G. | Caruso, J.F.

Article Type: Research Article

Abstract: BACKGROUND: Gender-based delta blood lactate concentration (Δ [BLa - ]) differences may be impacted by the volume of work performed during exercise. Thus workload can act as a confounding influence when data from men and women are compared. OBJECTIVE: To examine workload's impact on gender-based disparities in delta blood lactate concentration (Δ [BLa - ]) values from supramaximal exercise. METHODS: Subjects (49 women, 31 men) did two workouts on an exercise device (Impulse Technologies; Newnan, GA) comprised solely of either tonic or phasic repetitions. Total work (TW) and Δ [BLa - …] were quantified from each workout. TW and raw Δ [BLa - ] values were each examined with 2 × 2 ANOVAs, with repeated measures for workout. Δ [BLa - ] values were also examined with TW as a covariate using a 2 × 2 ANCOVA and repeated measures for workout. RESULTS: Raw Δ [BLa - ] and TW results each yielded predictable inter-gender differences. However our ANCOVA data produced a two-way interaction and the following significant differences: men-phasic, women-phasic > women-tonic > men-tonic. CONCLUSIONS: Our results support the idea that the volume of TW performed exacerbates inherent metabolic differences among men and women that heighten gender-based blood lactate differences. Future research on inter-gender lactate differences should consider workload as a covariate. Show more

Keywords: Total work, covariate, fatigue

DOI: 10.3233/IES-160615

Citation: Isokinetics and Exercise Science, vol. 24, no. 3, pp. 181-187, 2016

Authors: Park, Se-Yeon | Yoo, Won-Gyu

Article Type: Research Article

Abstract: BACKGROUND: The prone bridge is one of core stability exercises, which is important to maintain pelvic position as neutral. Elevated feet position is simple way to increase the external load, but have not been investigated the effect for muscle activity and pelvic position. OBJECTIVE: Present study is to investigate the effect of feet height on muscle activity and pelvic tilt angle during the prone bridge exercise. METHOD: Surface electromyographic responses of the rectus abdominis, internal oblique, erector spinae, serratus anterior, and pelvic anterior tilt angles were investigated during the prone bridge exercise with …step boxes of different heights under the feet. A total of 18 healthy, physically active female volunteers completed the normal prone bridge exercise (NP), prone bridge exercise with a low step box (PL), and prone bridge exercise with a high step box (PH). RESULTS: The PL condition caused significant increases in the activity of the internal oblique muscles compared with the NP condition (P < 0.05). PL and PH, which used step boxes, showed significantly greater activation in the serratus anterior compared to the NP (P < 0.05). The pelvic anterior tilt angle during PH was significantly greater than that during PL or NP (P < 0.05). CONCLUSION: The high step box increased the pelvic anterior tilt angle with no additional abdominal muscle activity. The prone bridge exercise could be effective by adopting horizontal position between upper and lower body, compared to inclined lower body and general position. Show more

Keywords: Abdominal muscle, electromyography, foot height, low back, pilates

DOI: 10.3233/IES-160616

Citation: Isokinetics and Exercise Science, vol. 24, no. 3, pp. 189-194, 2016

Authors: Kim, Kyoung | Cha, Yong-Jun | Fell, Dennis W.

Article Type: Research Article

Abstract: OBJECTIVE: To investigate the influence of two different active ankle positions during training on the strengths of knee extensors and flexors. METHODS: A sample of 21 healthy adults was randomized into ankle dorsiflexion (AD, N= 11) and ankle plantarflexion (AP, N= 10) training groups. Subjects were trained isokinetically and concentrically in knee extension and flexion under these two actively fixed, contracted ankle conditions, four times a week for three weeks. RESULTS: AD group showed significant strength improvements in both peak moment and total work. These improvements were also higher significantly, between 29-59% compared …to those gained by AP group. CONCLUSION: Active ankle dorsiflexion during concentric isokinetic knee strength training may be more efficient for improving knee extensors and flexors strength than a plantarflexed position. Show more

Keywords: Ankle position, strength training, multi-joint system, knee joint strength

DOI: 10.3233/IES-160617

Citation: Isokinetics and Exercise Science, vol. 24, no. 3, pp. 195-199, 2016

Authors: Le Goff, Caroline | Kaux, Jean-François | Laurent, Terry | Vannuscorps, Julien | Seidel, Laurence | Rodriguez de la Cruz, Carlos | Forthomme, Bénédicte | Bury, Thierry | Chapelle, Jean-Paul | Cavalier, Etienne | Croisier, Jean-Louis

Article Type: Research Article

Abstract: BACKGROUND: Regular physical activity is an important health factor, but intense physical stress can increase the risk of heart disease. OBJECTIVE: Our aim was to determine the potential cardiac repercussions of, and the oxidative stress resulting from a maximal eccentric isokinetic exercise and a 1-hour treadmill run at 75% V ˙ O2 max (maximal exercise done 6 weeks before). METHODS: Twelve young sedentary healthy subjects randomly performed two tests separated by 6 weeks: 1) 3 sets of 30 maximal eccentric isokinetic contractions of the quadriceps; 2) a 1-hour …running on treadmill at 75% V ˙ O2max max. We drew blood samples just before each exercise (T1), and just after (T2), 3 hours after (T3), and 24 hours after (T4) the end of each exercise to measure cardiac and oxidative stress biomarkers. RESULTS: In the running group, we observed significant differences for myoglobin (T3: 145 ± 80 μ g/L), creatinine kinase (T4: 593 ± 350 mg/L), oxidized glutathione (T2: 22 ± 15.6 μmol/L), and highly sensitive cardiac troponin T, (T3: 0.051 ± 0.038 ng/mL). In the isokinetic group, we observed significant differences for myoglobin (T3:1419 ± 2533 mg/L), creatine kinase (3303 ± 7159 mg/L), and oxidized glutathione (T4:24 ± 14 μ mol/L). Between isokinetic exercise and running, we observed significant differences for uric acid (p< 0.05, running > eccentric), myoglobin (p< 0.05, ditto), NT-proBNP (p< 0.05, ditto), hsTnT (p< 0.01, ditto), and oxidized glutathione (p< 0.05). CONCLUSIONS: As cardiac biomarkers appear practically unmodified after the isokinetic exercise, despite the considerable oxidative stress, we suggest that the application of intense maximal eccentric isokinetic exercise, when indicated, should be safe for most patients including those whose cardiac status is unknown. On the other hand, the increase in cardiac biomarkers observed after running, could reflect leakage of these biomarkers from the cytosolic pool of cardiac cells, linked to membrane damage, rather than the result of a major injury and hence running is supposed to be a safe practice. However, since sudden death during running has been previously described, assesment of the cardiac biomarkers and a follow-up by a sport doctor is important especially if there is a cardiac family history. Show more

Keywords: Cardiac biomarkers, isokinetic, maximal eccentric exercise, oxidative stress, running

DOI: 10.3233/IES-160618

Citation: Isokinetics and Exercise Science, vol. 24, no. 3, pp. 201-208, 2016

Authors: Ten Hoor, Gill A. | Musch, Kirsty | Meijer, Kenneth | Plasqui, Guy

Article Type: Research Article

Abstract: BACKGROUND: A single measure to characterize overall muscle strength is advantageous because it saves time and costs of evaluation. For this reason, the back-leg-chest (BLC) strength might be an appropriate single measure in characterizing total body strength. OBJECTIVE: To assess the test-retest reproducibility and smallest real difference (SRD) of the BLC dynamometer in healthy adults and adolescents and to examine whether handgrip, knee-extensor and knee-flexor strength predict BLC strength in healthy adults. METHODS: Forty-five adults and 58 adolescents were recruited. In a first session back-leg-chest strength, handgrip strength, and additionally, in adults, isometric …knee-extensor strength, and knee-flexor strength were measured. In a second session, 2-5 days later, BLC strength was measured again for test-retest reproducibility. RESULTS: Inter-session correlations of BLC strength were high (all r's and ICC's > 0.92). Bland-Altman-plots showed high agreement. The SRD and SRD% were between 14-26, and 19% and 26% respectively. Strength variables (handgrip, knee-extensor, and knee-flexor strength) explained 87% of the variance in BLC strength. A stepwise linear regression showed that dominant knee extensor and flexor strength were the most important significant predictors of BLC strength (r2 = 0.86). CONCLUSIONS: This study demonstrated that the BLC dynamometer has reasonably high test-retest reproducibility and hence may serve in some pertinent situations to be an appropriate tool for clinical, basic and applied research. Show more

Keywords: Back-leg-chest dynamometer, knee extensor strength, knee flexor strength, handgrip strength, dynamometry, reproducibility, validity

DOI: 10.3233/IES-160619

Citation: Isokinetics and Exercise Science, vol. 24, no. 3, pp. 209-216, 2016

Authors: Schoenfeld, Brad J. | Contreras, Bret | Vigotsky, Andrew D. | Ogborn, Dan | Fontana, Fabio | Tiryaki-Sonmez, Gul

Article Type: Research Article

Abstract: OBJECTIVE: The purpose of this study was to compare activation of the upper body musculature during the barbell bench press at varying training intensities. METHODS: Twelve young, resistance-trained men performed sets of the bench press to momentary muscular failure with two different loads: a high-load (HIGH) set at 80% of 1RM and a low-load (LOW) set at 50% 1RM. Exercise order was counterbalanced so that half the subjects performed the LOW condition first and the other half performed the HIGH first. Surface electromyography (EMG) was used to assess mean, peak, and iEMG muscle activation of the …anterior deltoid, triceps brachii, and sternal and clavicular heads of the pectoralis major. RESULTS: The main effects for trials were significant for mean EMG (p < 0.001) and iEMG matched (p < 0.001) favoring HIGH and iEMG total favoring LOW (p = 0.001) across all muscle groups in both conditions with varying effect sizes. All other main effects and interactions were not statistically significant. CONCLUSION: Despite similarities in peak EMG amplitude, the greater results for mean and iEMG matched in HIGH suggests that heavier loads may produce greater muscle activation. Show more

Keywords: Size principle, low-load, light weights, muscle hypertrophy, training intensity

DOI: 10.3233/IES-160620

Citation: Isokinetics and Exercise Science, vol. 24, no. 3, pp. 217-224, 2016

Authors: Özdal, Mustafa

Article Type: Research Article

Abstract: BACKGROUND: Respiratory muscles are important for exercise tolerance. Respiratory muscle fatigue (RMF) has a negative influence on exercise performance. OBJECTIVE: The aim of the present study was to examine the effects of a core strength training (CST) program on the RMF following incremental exercise. METHODS: Thirty male volleyball players participated in the study. The subjects were divided into two groups as experimental group (EG, n = 15) and control group (CG, n = 15). An eight-week CST program was implemented in the EG. The CG subjects participated in their respective sport training routine. …The maximal inspiratory pressure (MIP) was measured twice at the baseline and endline incremental exercise both before (pre-test) and after (post-test) the eight weeks. A reduction in the MIP between the baseline and endline incremental exercise was considered to be indicative of the RMF. RESULTS: There was a significant decrease in the MIP at the baseline and endline between the pre- and post-tests of both groups (p < 0.05). An increment in the MIP was found at the baseline between the pre- and post-tests in the EG (p < 0.05). There was no change in the RMF between the pre- and post-tests in the CG (p > 0.05). A significant decrease in the RMF was observed between the pre- and post- tests in the EG after the eight-week CST program (p < 0.05). CONCLUSIONS: These variations indicate that core strength training may positively affect both the strength and fatigue of respiratory muscles. Show more

Keywords: Respiratory muscles, maximal inspiratory pressure, fatigue, core strength, exercise

DOI: 10.3233/IES-160621

Citation: Isokinetics and Exercise Science, vol. 24, no. 3, pp. 225-230, 2016

Authors: Edouard, Pascal | Lardy, Guillaume | Damotte, Alexandre | Gasq, David

Article Type: Research Article

Abstract: BACKGROUND: Variations in both afferent proprioceptive information and efferent motor responses of the shoulder have been separately reported in overhead athletes. OBJECTIVES: We used a validated force platform method to examine shoulder sensorimotor control adaptation to overhead sports by analysing the change in Center of Pressure (CoP) in overhead athletes compared to control subjects. METHODS: Thirty healthy subjects were divided into four groups: squash players (SG), javelin throwers (JG) and two representative matched control groups of nonathletic healthy subjects, respectively. CoP displacements were measured by a force platform in the upper limb weight-bearing …position with the lower limbs resting on a table up to the anterior superior iliac spines. RESULTS: There were significant side-to-side differences for SG (P< 0.05); while not for JG and control groups. There were higher stabilometric values on the dominant side for SG and JG than their respective controls (P< 0.05). CONCLUSIONS: These preliminary results suggest that the thrower's shoulder variations could include and/or induce a deficiency in shoulder sensorimotor control of the throwing side. Show more

Keywords: Shoulder physical examination/instrumentation, sensorimotor system, posture, overhead sports

DOI: 10.3233/IES-160622

Citation: Isokinetics and Exercise Science, vol. 24, no. 3, pp. 231-236, 2016

Authors: Dziubek, Wioletta | Bulińska, Katarzyna | Rogowski, Ƚukasz | Kusztal, Mariusz | Zembroń-Ƚacny, Agnieszka | Goƚȩbiowski, Tomasz | Markowska, Dominika | Klinger, Marian | Woźniewski, Marek

Article Type: Research Article

Abstract: BACKGROUND: Patients with end-stage renal disease (ESRD) have poor physical performance and reduced exercise capacity due to frequent haemodialysis treatments. OBJECTIVE: The aim of the study was to determine the effectiveness of a three-month endurance training programme in patients with ESRD. METHODS: In order to improve both functional fitness and skeletal muscle properties, movement therapy-cycle ergometer, was applied in eligible ESRD patients during dialysis. The study included 40 dialysis patients, but only 27 patients completed the full three-month training during each haemodialysis treatment. Before and after training, all patients underwent observations according to …the established protocol: functional capacity - Six-Min Walk Test, agility - Timed Up and Go test, and muscle strength testing under isokinetic conditions at 60, 180 and 300°/s. RESULTS: Patients covered significantly longer distances in the 6MWT with a higher gait intensity after the 3 months training programme: the 6MWT increased from 360.8 to 390.2 m and metabolic equivalent from 2.74 to 2.85. The TUG significantly decreased in both women and men: from 9.07 to 7.51 s, and from 9.64 s to 7.4 s, respectively. The knee extension peak moment at 60 and 180°/s was significantly higher in women than in men following training. In addition, the women demonstrated more significant changes in flexor muscles at all angular velocities. CONCLUSIONS: Three-month endurance training was effective in patients with ESRD in improving both functional fitness and skeletal muscle properties. Show more

Keywords: End-stage renal disease (ESRD), 6MWT, muscle moment, physical training

DOI: 10.3233/IES-160623

Citation: Isokinetics and Exercise Science, vol. 24, no. 3, pp. 237-246, 2016