Browsing by Person "Eston, R."

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Assessment of neuromuscular performance using electromyography
(Routledge, 2008-10-21) Gleeson, Nigel; Eston, R.; Reilly, T.
About the book: Kinanthropometry is the study of human body size, shape and form and how those characteristics relate to human movement and sporting performance. In this fully updated and revised edition of the classic guide to kinanthropometric theory and practice, leading international sport and exercise scientists offer a clear and comprehensive introduction to essential principles and techniques.
Effect of flexibility training on symptoms of exercise-induced muscle damage: A preliminary study
(Hong Kong Association of Sports Medicine & Sports Science, 2007) Eston, R.; Rowlands, A. V.; Coulton, D.; Mckinney, J.; Gleeson, Nigel
Exercise-induced muscle damage (EIMD) is characterized by loss of strength, increase In muscle stiffness, swelling, and soreness. The aim of this study was to assess the effects of flexibility training of the hamstring muscle group on symptoms of EIMD. Fourteen males (mean standard deviation: age = 20.6 0.8 years; mass = 77.3 10.4 kg; height = 1.77 0.05 m) were randomly assigned to a 5-week flexibility (proprioceptive neuromuscular facilitation [PNF]) training or control group. Pre- and post-measures of peak static muscle force at knee joint angles representing decreasing muscle lengths of the hamstrings (25 deg, 30 deg, 40 deg, 80 deg) and flexibility were taken. Flexibility increased significantly following PNF flexibility training (pre-test = 19.4 6.2 cm, post-test = 26.6 6.9 cm), whereas it stayed constant in the control group (pre-test = 16.0 9.3 cm, post-test = 16.7 7.6 cm). Both groups underwent a damaging exercise protocol incorporating six sets of 10 isokinetic eccentric contractions of the hamstrings. Measurements of isometric strength, flexibility, and perceived soreness were recorded prior to and 1, 24, 48 and 72 hours after damage. There was a tendency for the PNF group to recover from strength loss earlier at longer muscle lengths (25 deg, p = 0.06; 30 deg, p = 0.05), but not at shorter muscle lengths. There was no evidence of a protective effect of PNF training on flexibility and soreness. In conclusion, an increase in flexibility of the hamstring muscle group led to some protection from strength loss at long muscle lengths following EIMD.
Effects of acute fatigue on the volitional and magnetically-evoked electromechanical delay of the knee flexors in males and females
(Springer Verlag, 2007-07) Minshull, Claire; Gleeson, Nigel; Walters-Edwards, M.; Eston, R.; Rees, D.
Neuromuscular performance capabilities, including those measured by evoked responses, may be adversely affected by fatigue; however, the capability of the neuromuscular system to initiate muscle force rapidly under these circumstances is yet to be established. Sex-differences in the acute responses of neuromuscular performance to exercise stress may be linked to evidence that females are much more vulnerable to anterior cruciate ligament injury than males. Optimal functioning of the knee flexors is paramount to the dynamic stabilisation of the knee joint, therefore the aim of this investigation was to examine the effects of acute maximal intensity fatiguing exercise on the voluntary and magnetically-evoked electromechanical delay in the knee flexors of males and females. Knee flexor volitional and magnetically-evoked neuromuscular performance was assessed in seven male and nine females prior to and immediately after: (1) an intervention condition comprising a fatigue trial of 30-s maximal static exercise of the knee flexors, (2) a control condition consisting of no exercise. The results showed that the fatigue intervention was associated with a substantive reduction in volitional peak force that was greater in males compared to females (15.0, 10.2%, respectively, P < 0.01) and impairment to volitional electromechanical delay in females exclusively (19.3%, P < 0.05). Similar improvements in magnetically-evoked electromechanical delay in males and females following fatigue (21%, P < 0.001), however, may suggest a vital facilitatory mechanism to overcome the effects of impaired voluntary capabilities, and a faster neuromuscular response that can be deployed during critical times to protect the joint system.
Effects of antecedent flexibility conditioning on neuromuscular and sensorimotor performance during exercise-induced muscle damage
(Hong Kong Association of Sports Medicine & Sports Science, 2013-12) Gleeson, Nigel; Eston, R.; Minshull, Claire; Bailey, A.; Al Kitani, Abdul Hameed; Darain, Haider; Yates, C.; Rees, D.
The aim of this study was to assess the effects of two modes of antecedent flexibility conditioning on neuromuscular and sensorimotor performance during a subsequent episode of exercise-induced muscle damage (EIMD). Twenty-four males (age 20.9 2.3 years; height 1.78 0.06 m; body mass 72.3 7.4 kg, mean SD) were randomly assigned to interventions comprising 6 weeks of thrice-weekly flexibility conditioning of the hip region and knee flexor musculature in the dominant limb involving proprioceptive neuromuscular facilitation (n = 8), passive exercise (n = 8), or no exercise as a control (n = 8). Musculoskeletal, neuromuscular, and sensorimotor assessments were carried out at baseline, after conditioning, and before and up to 168 hours after damaging exercise of the ipsilateral knee flexors. Flexibility conditioning and EIMD elicited transient performance decreases in volitional electromechanical delay (up to 40.1% compared to baseline; 67.5 12.3 milliseconds vs. 47.9 9.7 milliseconds, mean SD, 48-hour post- vs. pre-EIMD; p < 0.01), passive hip flexibility (up to 19.9%; 96.7 8.2 vs. 120.7 11.0, p < 0.001) and sensorimotor capability (manifold error increase to 10.8%; 10.8% 6.9% vs. 0.3% 3.7%, p < 0.05) and exceeded the effects of eccentric exercise alone. EIMD-related performance decreases were especially prominent when preceded by passive flexibility conditioning, and were sufficiently potent following both modes of antecedent conditioning to raise concerns about compromised capability for rapid and dynamic stabilization of synovial joints. 2013.
Knee joint neuromuscular activation performance during muscle damage and superimposed fatigue
(Taylor & Francis, 2012-06) Minshull, Claire; Eston, R.; Rees, D.; Gleeson, Nigel
This study examined the concurrent effects of exercise-induced muscle damage and superimposed acute fatigue on the neuromuscular activation performance of the knee flexors of nine males (age: 26.76.1 years; height 1.810.05 m; body mass 81.211.7 kg [means]). Measures were obtained during three experimental conditions: (i) 'fatigue-muscle damage', involving acute fatiguing exercise performed on each assessment occasion plus a single episode of eccentric exercise performed on the first occasion and after the fatigue trial; (ii) 'fatigue', involving the fatiguing exercise only; and (iii) 'control' consisting of no exercise. Assessments were performed prior to (pre) and at 1 h, 24 h, 48 h, 72 h, and 168 h relative to the muscle damaging eccentric exercise. Repeated-measures analyses of variance (ANOVAs) showed that muscle damage elicited reductions of up to 38%, 24% and 65% in volitional peak force, electromechanical delay and rate of force development compared to baseline and controls, respectively (F [10, 80] = 2.3 to 4.6; P < 0.05) with further impairments (6.2% to 30.7%) following acute fatigue (F [2, 16] = 4.3 to 9.1; P < 0.05). By contrast, magnetically-evoked electromechanical delay was not influenced by muscle damage and was improved during the superimposed acute fatigue (~14%; F [2, 16] = 3.9; P < 0.05). The safeguarding of evoked muscle activation capability despite compromised volitional performance might reveal aspects of capabilities for emergency and protective responses during episodes of fatigue and antecedent muscle damaging exercise. 2012 Copyright Taylor and Francis Group, LLC.
Repeated exercise stress impairs volitional but not magnetically evoked electromechanical delay of the knee flexors
(Taylor & Francis, 2012-01) Minshull, Claire; Eston, R.; Bailey, A.; Rees, D.; Gleeson, Nigel
The effects of serial episodes of fatigue and recovery on volitional and magnetically evoked neuromuscular performance of the knee flexors were assessed in 20 female soccer players during: (i) an intervention comprising 4 35 s maximal static exercise, and (ii) a control condition. Volitional peak force was impaired progressively (~16% vs. baseline: 235.3 54.7 to 198.1 38.5 N) by the fatiguing exercise and recovered to within ~97% of baseline values following 6 min of rest. Evoked peak twitch force was diminished subsequent to the fourth episode of exercise (23.3%: 21.4 13.8 vs. 16.4 14.6 N) and remained impaired at this level throughout the recovery. Impairment of volitional electromechanical delay performance following the first episode of exercise (25.5%: 55.3 11.9 vs. 69.5 24.5 ms) contrasted with concurrent improvement (10.0%: 24.5 4.7 vs. 22.1 5.0 ms) in evoked electromechanical delay (P < 0.05), and this increased disparity between evoked and volitional electromechanical delay remained during subsequent periods of intervention and recovery. The fatiguing exercise provoked substantial impairments to volitional strength and volitional electromechanical delay that showed differential patterns of recovery. However, improved evoked electromechanical delay performance might identify a dormant capability for optimal muscle responses during acute stressful exercise and an improved capacity to maintain dynamic joint stabilty during critical episodes of loading. 2012 Taylor & Francis.
Single measurement reliability and reproducibility of volitional and magnetically-evoked indices of neuromuscular performance in adults
(Elsevier, 2009) Minshull, Claire; Gleeson, Nigel; Eston, R.; Bailey, A.; Rees, D.
This study documents intra-session and inter-day reproducibility (coefficient of variation [V%]) and single measurement reliability (intra-class correlations [RI]; standard error of a single measurement [SEM%] [95% confidence limits]) of indices of neuromuscular performance elicited during peripheral nerve magnetic stimulation. Twelve adults (five men and seven women) completed 3 assessment sessions on 3 days, during which multiple assessments of knee flexor volitional and magnetically-evoked indices of electromechanical delay (EMDV; EMDE), rate of force development (RFDV; RFDE), peak force (PFV; PTFE), and compound muscle action potential latency (LATE) and amplitude (AMPE) were obtained. Results showed that magnetically-evoked indices of neuromuscular performance offered statistically equivalent levels of measurement reproducibility (V%: 4.3-31.2%) and reliability (RI: 0.98-0.51) compared to volitional indices (V%: 3.7-25.2%; RI: 0.98-0.64), which support the efficacy of both approaches to assessment and the indices PFV, EMDV, EMDE and LATE offer the greatest practical utility for assessing neuromuscular performance.
Single measurement reliability and reproducibility of volitional and magnetically-evoked indices of neuromuscular performance in adults
(Elsevier, 2009-10) Gleeson, Nigel; Minshull, Claire; Eston, R.; Bailey, A.; Rees, D.
This study documents intra-session and inter-day reproducibility (coefficient of variation [V%]) and single measurement reliability (intra-class correlations [RI]; standard error of a single measurement [SEM%] [95% confidence limits]) of indices of neuromuscular performance elicited during peripheral nerve magnetic stimulation. Twelve adults (five men and seven women) completed 3 assessment sessions on 3 days, during which multiple assessments of knee flexor volitional and magnetically-evoked indices of electromechanical delay (EMDV; EMDE), rate of force development (RFDV; RFDE), peak force (PFV; PTFE), and compound muscle action potential latency (LATE) and amplitude (AMPE) were obtained. Results showed that magnetically-evoked indices of neuromuscular performance offered statistically equivalent levels of measurement reproducibility (V%: 4.3–31.2%) and reliability (RI: 0.98–0.51) compared to volitional indices (V%: 3.7–25.2%; RI: 0.98–0.64), which support the efficacy of both approaches to assessment and the indices PFV, EMDV, EMDE and LATE offer the greatest practical utility for assessing neuromuscular performance.
Skeletal muscle function
(Routledge, 2008-10-21) Baltzopoulos, V.; Gleeson, Nigel; Eston, R.; Reilly, T.
About the book: Kinanthropometry is the study of human body size, shape and form and how those characteristics relate to human movement and sporting performance. In this fully updated and revised edition of the classic guide to kinanthropometric theory and practice, leading international sport and exercise scientists offer a clear and comprehensive introduction to essential principles and techniques.
The differential effects of PNF versus passive stretch conditioning on neuromuscular performance
(European College of Sport Science, 2014-04) Minshull, Claire; Eston, R.; Bailey, A.; Rees, D.; Gleeson, Nigel
The effects of flexibility conditioning on neuromuscular and sensorimotor performance were assessed near to full knee extension (25). Eighteen males who were randomly assigned into two groups underwent eight weeks (three-times per week) of flexibility conditioning (hip region/knee flexor musculature; dominant limb) involving either proprioceptive neuromuscular facilitation (PNF) (n=9) or passive stretching (PASS) (n=9). Both modes of flexibility conditioning are popular within contemporary exercise and clinical settings and have demonstrated efficacy in improving range of motion. The contralateral limb and a prior 'no exercise' condition were used as controls. The PNF and PASS modes of conditioning improved passive hip flexibility to a similar extent (mean 19.3% vs. baseline, intervention limb, p<0.01) but did not alter knee flexor strength (overall mean 309.681 N) or sensorimotor performance (force and positional errors: 2.38.2% and 0.487.1%). Voluntary and magnetically evoked electromechanical delays (EMDV and EMDE, respectively) were increased but to a greater extent following PASS compared to PNF (PASS: 10.8% and 16.9% lengthening of EMDV and EMDE, respectively vs. PNF: 3.2% and 6.2%, p<0.01).The attenuated change to electromechanical delay (EMD) performance during PNF conditioning suggests a preserved capability for rapid muscle activation, which is important in the maintenance of dynamic joint stability. That PNF was also equally efficacious in flexibility conditioning would suggest that this mode of flexibility training should be used over passive to help preserve dynamic joint stability capabilities at this extended and vulnerable joint position. 2013 Copyright European College of Sport Science.
The effects of non-concurrent strength and endurance rehabilitation on the neuromuscular and musculoskeletal performance of knees treated with autologous chondrocyte implantation (ACI).
(International Society of Arthroscopy, Knee Surgery and Orthopaedic Sports Medicine, 2007-05) Bailey, A.; Gleeson, Nigel; Rees, D.; Roberts, S.; Eston, R.; Richardson, J.
ACI remains a relatively new surgical technique for the treatment of chondral lesions in the knee. Studies are on going to provide evidence for the ideal tissue engineering and surgical techniques leading to the growth of hyaline cartilage. However, the post- operative rehabilitation plays an equal and important role in the outcome of the procedure. No studies to date have systematically addressed the utility and efficacy of post-surgical ACI rehabilitation, aimed specifically at improving physiological, functional and self-perceived capability. Neither are there any studies investigating whether or not the physiological processes, associated with concurrent conditioning for endurance performance, have been shown to attenuate strength performance or affect other indices of neuromuscular performance.
The effects of plyometric exercise on unilateral balance performance
(Taylor & Francis, 2008-08) Twist, Craig; Gleeson, Nigel; Eston, R.
The purpose of this study was to determine the effects of plyometric exercise on unilateral balance performance. Nine healthy adults performed baseline measurements on the dominant limb that consisted of: a 20-s unilateral stability test on a tilt balance board, where a higher stability index represented deterioration in balance performance; isokinetic plantar flexion torque at 0.52 and 3.14 rad s-1; muscle soreness in the calf region; and resting plantar flexion angle. Plyometric exercise consisted of 200 counter-movement jumps designed to elicit symptoms of muscle damage, after which baseline measurements were repeated at 30 min, 24, 48, and 72 h. Perceived muscle soreness of the calf region increased significantly following the plyometric exercise protocol (F4,32 = 17.24, P < 0.01). Peak torque was significantly reduced after the plyometric exercise protocol (F4,32 = 7.49, P < 0.05), with greater loss of force at the lower angular velocity (F4,32 = 3.46, P < 0.05), while resting plantar flexion angle was not significantly altered compared with baseline values (P > 0.05). The stability index was significantly increased (F4,32 = 3.10, P < 0.05) above baseline (mean 2.3, s = 0.3) at 24 h (3.3, s = 0.4), after which values recovered. These results indicate that there is a latent impairment of balance performance following a bout of plyometric exercise, which has implications for both the use of skill-based activities and for increased injury risk following high-intensity plyometric training.