Browsing by Person "Minshull, Claire"

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A Systematic Review of the Role of Vitamin D on Neuromuscular Remodelling Following Exercise and Injury
(Springer, 2015-12-19) Minshull, Claire; Biant, Leela C.; Ralston, Stuart H.; Gleeson, Nigel
Vitamin D is important for skeletal muscle health and deficiency is associated with clinical neuromuscular symptoms of poor strength and gait. Supplementation can independently increase muscle strength in chronically deficient populations. However, the regulatory role of vitamin D on neuromuscular remodelling and adaptation subsequent to exercise conditioning or injury has not been systematically reviewed. Objective: to systematically review the available evidence of the role of vitamin D on neuromuscular remodelling following exercise conditioning, exercise- or experimentally induced injury. We searched Medline (OVID platform), PubMed, Embase and Web of Science for randomised controlled trials (RCTs) including measures of neuromuscular function, injury and/or inflammation; a physiologically stressful intervention involving exercise conditioning, exercise- or experimentally induced injury and; vitamin D supplementation. Nine RCTs met the inclusion criteria. Significant heterogeneity of methodological approaches and outcomes meant that meta-analysis of data was limited. Qualitative findings indicated that vitamin D may be an effective accelerant of neuromuscular remodelling in animal models (24-140 % improved recovery vs. control); the effects in humans are inconclusive and likely influenced by baseline vitamin D and supplementation strategy. Results of the meta-analyses indicated no effect of vitamin D supplementation on muscle strength adaptation following resistance training [standardised mean difference (SMD): 0.74, P = 0.42] or muscle damage (SMD: -0.03, P = 0.92), although inflammatory markers were elevated in the latter (SMD: 0.56, P = 0.04). Data from animal models offer promising and plausible mechanisms for vitamin D as an agent for neuromuscular adaptation. Further high-quality research is needed to offer clearer insight into the influential role of vitamin D in human populations.
Congruency and responsiveness of perceived exertion and time-to-end-point during an intermittent isometric fatigue task
(Springer Verlag, 2013-04) Shepherd, J.; Gleeson, Nigel; Minshull, Claire
The aims of this study were (1) to investigate the relationship between self-perception of effort and task duration in an intermittent isometric fatigue trial (IIF) and (2) to evaluate the capability of two assessment paradigms (perceived exertion; perceived task duration) to reflect changes in IIF intensity. Fifteen participants performed two IIF tasks of the knee extensors at intensities of 60 and 70 % of daily peak force, each separated by 48-72 h. Ordering of the tasks was counter-balanced and participants were blinded to the precise intensity of each IIF. A category-ratio scale (CR-10) and visual analogue scale were used during each IIF task to record measures of perceived exertion and perceived task duration, respectively. Measures were recorded at 10 % intervals across the relative duration of each IIF task. Pearson product-moment correlation coefficients revealed strong positive correlations (r > 0.99; p < 0.01) between completed task duration and both perceptual scales at the two IIF intensities. Separate two-way repeated measures ANOVAs of CR-10 and perceived task duration responses revealed significant main effects for time only (F [2.2,30.1] = 126.8; p < 0.001; F [2.6,36.8] = 117.2; p < 0.001, CR-10 and perceived task duration, respectively). The results suggest that perceived exertion and perceived task duration are equally effective predictors of IIF end-point. However, neither measure was sufficiently responsive to discriminate between 10 % changes in exercise intensity. 2012 Springer-Verlag.
Considerations of the Principles of Resistance Training in Exercise Studies for the Management of Knee Osteoarthritis: A Systematic Review
(W.B. Saunders, 2017-03-31) Minshull, Claire; Gleeson, Nigel
Objective: To evaluate the methodologic quality of resistance training interventions for the management of knee osteoarthritis. Data Sources: A search of the literature for studies published up to August 10, 2015, was performed on MEDLINE (OVID platform), PubMed, Embase, and Physiotherapy Evidence Database databases. Search terms associated with osteoarthritis, knee, and muscle resistance exercise were used. Study Selection: Studies were included in the review if they were published in the English language and met the following criteria: (1) muscle resistance training was the primary intervention; (2) randomized controlled trial design; (3) treatment arms included at least a muscle conditioning intervention and a nonexercise group; and (4) participants had osteoarthritis of the knee. Studies using preoperative (joint replacement) interventions with only postoperative outcomes were excluded. The search yielded 1574 results. The inclusion criteria were met by 34 studies. Data Extraction: Two reviewers independently screened the articles for eligibility. Critical appraisal of the methodology was assessed according to the principles of resistance training and separately for the reporting of adherence using a specially designed scoring system. A rating for each article was assigned. Data Synthesis: There were 34 studies that described a strength training focus of the intervention; however, the principles of resistance training were inconsistently applied and inadequately reported across all. Methods for adherence monitoring were incorporated into the design of 28 of the studies, but only 13 reported sufficient detail to estimate average dose of exercise. Conclusions: These findings affect the interpretation of the efficacy of muscle resistance exercise in the management of knee osteoarthritis. Clinicians and health care professionals cannot be confident whether nonsignificant findings are because of the lack of efficacy of muscle resistance interventions, or occur through limitations in treatment prescription and patient adherence. Future research that seeks to evaluate the effects of muscle strength training interventions on symptoms of osteoarthritis should be properly designed and adherence diligently reported. 2016 American Congress of Rehabilitation Medicine.
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.
Explosive hamstrings-to-quadriceps force ratio of males versus females
(2014-12) Hannah, Ricci; Folland, Jonathan P.; Smith, Stephanie L.; Minshull, Claire
Purpose: Females are known to exhibit a greater risk of ACL injury compared to males. Lower explosive hamstrings-to-quadriceps (H/Q) force ratio in the first 150 ms from activation onset could reflect an impaired capacity for knee joint stabilisation and increased risk of ACL injury. However, the explosive H/Q force ratio has not been compared between the sexes. Methods: The neuromuscular performance of untrained males and females (20 of each) was assessed during a series of isometric knee flexor and extensor contractions, specifically explosive and maximum voluntary contractions of each muscle group. Force, in absolute terms and normalised to body mass, and surface EMG of the hamstrings and quadriceps were recorded. Hamstrings force was expressed relative to quadriceps force to produce ratios of explosive H/Q force and H/Q maximum voluntary force (MVF). For the explosive contractions, agonist electromechanical delay (EMD) and agonist neural activation were also assessed. Results: The H/Q MVF ratio was greater in males (56 %) than females (50 %; P < 0.001). However, the explosive H/Q force ratio was similar between the sexes at each time point (25-150 ms) from activation onset. Explosive hamstrings, but not quadriceps, force relative to body mass was greater for males compared to females. There were no sex differences in EMD or agonist activation for either of the muscle groups. Conclusions: The lack of a sex difference in early phase isometric explosive H/Q force ratio suggests other factors might be more important in determining the substantially higher knee injury rates of females.
Improvement of Outcomes With Nonconcurrent Strength and Cardiovascular-Endurance Rehabilitation Conditioning After ACI Surgery to the Knee
(Human Kinetics Publishers Inc., 2014-08) Bailey, Andrea Kay; Minshull, Claire; Richardson, James; Gleeson, Nigel
Context: Autologous chondrocyte implantation (ACI) aims to restore hyaline cartilage. Traditionally, ACI rehabilitation is prescribed in a concurrent (CON) format. However, it is well known from studies in asymptomatic populations that CON training produces an interference effect that can attenuate strength gains. Strength is integral to joint function, so adopting a nonconcurrent (N-CON) approach to ACI rehabilitation might improve outcomes. Objective: To assess changes in function and neuromuscular performance during 48 wk of CON and N-CON physical rehabilitation after ACI to the knee. Setting: Orthopedic Hospital NHS Foundation Trust. Design: Randomized control, pilot study. Participants: 11 patients (9 male, 2 female age 32.3 6.6 y; body mass 79.3 10.4 kg; time from injury to surgery 7.1 4.9 mo [mean SD]) randomly allocated to N-CON:CON (2:1). Interventions: Standardized CON and N-CON physiotherapy that involved separation of strength and cardiovascular-endurance conditioning. Main Outcome Measures: Function in the single-leg-hop test, patient-reported outcomes (Knee injury and Osteoarthritis Outcome Score [KOOS], International Knee Documentation Committee subjective questionnaire [IKDC]), and neuromuscular outcomes of peak force (PF), rate of force development (RFD), electromechanical delay (EMD), and sensorimotor performance (force error [FE]) of the knee extensors and flexors of the injured and noninjured legs, measured presurgery and at 6, 12, 24, and 48 wk postsurgery. Results: Factorial ANOVAs with repeated measures of group by leg and by test occasion revealed significantly superior improvements for KOOS, IKDC, PF, EMD, and FE associated with N-CON vs CON rehabilitation (F1.5,13.4 GG = 3.7-4.7, P < .05). These results confirm increased peak effectiveness of N-CON rehabilitation (~4.5-13.3% better than CON over 48 wk of rehabilitation). N-CON and CON showed similar patterns of improvement for single-leg-hop test and RFD. Conclusions: Nonconcurrent strength and cardiovascular-endurance conditioning during 48 wk of rehabilitation after ACI surgery elicited significantly greater improvements to functional and neuromuscular outcomes than did contemporary concurrent rehabilitation.
Influence of surgery and rehabilitation conditioning on psychophysiological fitness
(Hong Kong Association of Sports Medicine & Sports Science, 2008) Gleeson, Nigel; Parfitt, G.; Minshull, Claire; Bailey, A.; Rees, D.
The purpose of this study was to assess changes in psychophysiological fitness following reconstructive knee surgery and early phase (2.5 months) physical rehabilitation. Nine patients (7 male, 2 female; mean age, 29.9 years) electing to undergo anterior cruciate ligament reconstructive surgery (central third, bone-patella tendon-bone graft) were assessed on four separate assessment occasions post-surgery. Repeated measures ANOVAs showed significant condition (injured/non-injured leg) by test occasion (2 weeks pre-surgery and 6, 8 and 10 weeks post-surgery) interactions for knee ligamentous compliance (anterior tibiofemoral displacement), peak force and electromechanical delay associated with the knee flexors of the injured and non-injured legs (F3,24 = 4.7 to 6.6; p < 0.01), together with individualized emotional profile disturbance scores that were significantly less at 10 weeks post-surgery compared to pre-surgery, 6 weeks and 8 weeks post-surgery (F3,4 = 7.6,; p < 0.01). Spearman rank correlation coefficients identified significant relationships between musculoskeletal fitness and emotional profile scores at pre-surgery (r = 0.69-0.72; p < 0.05) and at 8 weeks post-surgery (r = 0.70-0.73; p < 0.05). The 6 Bi-POMS subscales and the 12 ERAIQ responses found Inconsistent patterns of response and relationships across the assessment occasions. Overall, the patterning of changes and associations amongst emotional performance profile discrepancy scores in conjunction with those scores from indices of musculoskeletal fitness performance capability offered important support for the efficacy of an approach which integrates self-perceptive and objective measurements of fitness capability during rehabilitation following surgery to a synovial joint.
Joint angle affects volitional and magnetically-evoked neuromuscular performance differentially
(Elsevier, 2011-08) Gleeson, Nigel; Minshull, Claire; Williamson, D.; Rees, D.
This study examined the volitional and magnetically-evoked neuromuscular performance of the quadriceps femoris at functional knee joint angles adjacent to full extension. Indices of volitional and magnetically-evoked neuromuscular performance (N=15 healthy males, 23.52.9years, 71.55.4kg, 176.55.5cm) were obtained at 25, 35 and 45 of knee flexion. Results showed that volitional and magnetically-evoked peak force (PFV and PTFE, respectively) and electromechanical delay (EMDV and EMDE, respectively) were enhanced by increased knee flexion. However, greater relative improvements in volitional compared to evoked indices of neuromuscular performance were observed with increasing flexion from 25 to 45 (e.g. EMDV, EMDE: 36% vs. 11% improvement, respectively; F[2,14]=6.8, p<0.05). There were no significant correlations between EMDV and EMDE or PFV and PTFE, at analogous joint positions. These findings suggest that the extent of the relative differential between volitional and evoked neuromuscular performance capabilities is joint angle-specific and not correlated with performance capabilities at adjacent angles, but tends to be smaller with increased flexion. As such, effective prediction of volitional from evoked performance capabilities at both analogous and adjacent knee joint positions would lack robustness. 2011 Elsevier Ltd.
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.
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.