Acceptability of a progressive resistance training programme for ambulatory adolescents with spastic cerebral palsy in England: a qualitative study.

PURPOSE: The aim of this study was to explore the acceptability of a 10-week progressive resistance training programme from the perspective of ambulatory adolescents with CP and physiotherapists. MATERIAL AND METHODS: Semi-structured interviews were conducted with 32 adolescents with spastic CP, aged 10-19 years in Gross Motor Function Classification System (GMFCS) levels I-III, and 13 physiotherapists. Adolescents had completed a 10-week progressive resistance training programme and physiotherapists had delivered the programme. The Framework Method was used to analyse data. RESULTS: The analysis identified four themes. "It's do-able" described the acceptability of the programme structure, including the frequency of sessions and the duration of the programme. "They were difficult but I did it" described the acceptability of the exercises. "It is completely different," explored the experience of using equipment to progress the programme and "I wish I could do it on a permanent basis" discussed continuing to participate in resistance training. CONCLUSIONS: Findings suggest that resistance training is largely acceptable to adolescents and physiotherapists. Acceptability was enhanced by having a weekly supervised session and being able to adapt and progress the exercises to meet the individual's ability. However, there are challenges to implementing progressive resistance training as part of routine practice.Clinical trial registration number: ISRCTN90378161.

Progressive resistance training is largely acceptable to ambulatory adolescents with cerebral palsy and physiotherapists.Adolescents' ability to complete the exercises increased their confidence and motivated them to continue with the programme.Adolescents valued being supervised by a physiotherapist and believed they needed a physiotherapist to progress the exercises and motivate them to perform to their maximum capacity.Within the National Health Service (NHS), limited time and equipment may prevent implementation of resistance training for adolescents with CP in accordance with guidelines.A short-term resistance training programme delivered by physiotherapists in the NHS may provide the foundation for continuing participation in resistance training in a community setting.

Building for the Future: A Systematic Review of the Effects of Eccentric Resistance Training on Measures of Physical Performance in Youth Athletes.

BACKGROUND: Eccentric resistance training is recognised as an effective stimulus for enhancing measures of muscular strength and power in adult populations; however, its value in youth athletes is currently not well understood. OBJECTIVE: The aim of this systematic review was to critically appraise the effects of eccentric resistance training on measures of physical performance (i.e. muscular strength, jump, sprint and change of direction) in youth athletes 18 years of age and under. METHODS: Original journal articles published between 1950 and June 2022 were retrieved from electronic search engines of PubMed, SPORTDiscus and Google Scholar's advanced search option. Full journal articles investigating the acute and chronic effects of eccentric resistance training on measures of physical performance in youth athletes (i.e. a person 18 years of age or under who competes in sport) were included. The methodological quality and bias of each study were assessed prior to data extraction using a modified Downs and Black checklist. RESULTS: The search yielded 749 studies, of which 436 were duplicates. Three-hundred studies were excluded based upon title and abstract review and a further 5 studies were removed following the modified Downs and Black checklist. An additional 14 studies were identified during backward screening. Accordingly, 22 studies were included in our systematic review. The Nordic hamstring exercise and flywheel inertial training were the most frequently used eccentric resistance training methods in youth athletes. Improvements in physical performance following the Nordic hamstring exercise are dependent upon an increase in the breakpoint angle, rather than training volume (sets and repetitions), and are further elevated with the addition of hip extension exercises or high-speed running. A minimum of 3 familiarisation trials is necessary to elicit meaningful adaptations following flywheel inertial training. Furthermore, an emphasis should be placed upon decelerating the rotating flywheel during the final one to two thirds of the eccentric phase, rather than gradually throughout the entire eccentric phase. CONCLUSIONS: The findings of this systematic review support the inclusion of eccentric resistance training in youth athletes to improve measures of muscular strength, jump, sprint and change of direction performance. The current eccentric resistance training methods are predominantly limited to the Nordic hamstring exercise and flywheel inertial training; however, the efficacy of accentuated eccentric loading to improve jump performance warrants attention in future investigations.

Concurrent Validity of Lower Limb Muscle Strength by Handheld Dynamometry in Children 7 to 11 Years Old.

CONTEXT: The assessment of pediatric muscle strength is necessary in a range of applications, including rehabilitation programs. Handheld dynamometry (HHD) is considered easy to use, portable, and low cost, but validity to measure lower limb muscle strength in children has not been assessed. OBJECTIVE: To determine the concurrent validity of lower limb torque from HHD compared with isokinetic dynamometry (ID) in children aged from 7 to 11 years old. DESIGN: A descriptive assessment of concurrent validity of lower limb joint torques from HHD compared with ID. METHODS: Sixty-one typically developing children underwent assessment of maximal hip, knee, and ankle isometric torque by HHD and ID using standardized protocols. Joint positions were selected to represent maximal strength and were replicated between devices. Concurrent validity was determined by Pearson correlation, limits of agreement, and Bland-Altman plots. RESULTS: Correlations between HHD and ID were moderate to large for knee extension (r 95% CI, .39 to .73), small to large for plantar flexion (r 95% CI, .29 to .67), knee flexion (r 95% CI, .16 to .59), hip flexion (r 95% CI, .21 to .57), hip extension (r 95% CI, .18 to .54), and hip adduction (r 95% CI, .12 to .56), and small to moderate for dorsiflexion (r 95% CI, -.11 to .39) and hip abduction (r 95% CI, -.02 to .46). Limits of agreement for all joint torques were greater than 10% indicating large error in HHD measured torque compared with ID. A positive proportional bias was detected for plantarflexion, indicating that HHD underestimated torque to a greater extent in participants with higher torque values. CONCLUSIONS: Maximal torque values from HHD and ID are consistent with those previously reported in the literature. Poor concurrent validity of HHD may have arisen from issues around joint position, joint stabilization, and the experience of the tester to prevent an isokinetic contraction. Pediatric lower limb muscle strength assessed by HHD should be interpreted with caution.

The Need for Eccentric Speed: A Narrative Review of the Effects of Accelerated Eccentric Actions During Resistance-Based Training.

Eccentric training as a method to enhance athletic performance is a topic of increasing interest to both practitioners and researchers. However, data regarding the effects of performing the eccentric actions of an exercise at increased velocities are limited. This narrative review aimed to provide greater clarity for eccentric methods and classification with regard to temporal phases of exercises. Between March and April 2021, we used key terms to search the PubMed, SPORTDiscus, and Google Scholar databases within the years 1950-2021. Search terms included 'fast eccentric', 'fast velocity eccentric', 'dynamic eccentric', 'accentuated eccentric loading', and 'isokinetic eccentric', analysing both the acute and the chronic effects of accelerated eccentric training in human participants. Review of the 26 studies that met the inclusion criteria identified that completing eccentric tempos of < 2 s increased subsequent concentric one repetition maximum performance, velocity, and power compared with > 4 s tempos. Tempos of > 4 s duration increased time under tension (TUT), whereas reduced tempos allowed for greater volume to be completed. Greater TUT led to larger accumulation of blood lactate, growth hormone, and testosterone when volume was matched to that of the reduced tempos. Overall, evidence supports eccentric actions of < 2 s duration to improve subsequent concentric performance. There is no clear difference between using eccentric tempos of 2-6 s if the aim is to increase hypertrophic response and strength. Future research should analyse the performance of eccentric actions at greater velocities or reduced time durations to determine more factors such as strength response. Tempo studies should aim to complete the same TUT for protocols to determine measures for hypertrophic response.

Physiological and thermoregulatory effects of oral taurine supplementation on exercise tolerance during forced convective cooling.

AbstractWe investigated the effects of taurine supplementation on cycling time to exhaustion in cold conditions. Eleven males cycled to exhaustion at a power output equivalent to the mid-point between ventilatory threshold and maximum aerobic power following 15-min rest in the cold (apparent temperature of ∼ 4°C; air flow of 4.17 m s-1). Two hours before, participants ingested taurine (50 mg·kg-1) or placebo beverage. Pulmonary gases, carbohydrate (CHO) and fat oxidation, body temperatures, mean local sweat rate, heart rate, rate of perceived exertion (RPE) and thermal comfort were recorded. Time to exhaustion was not different between trials (taurine = 14.6 ± 4.7 min; placebo = 13.4 ± 5.6 min, P = 0.061, d = 0.27). There were no effects (P > 0.05) of taurine on core temperature, mean skin temperature or local sweat rates. However, the placebo condition showed greater (P < 0.05) reductions in arm-to-finger temperature gradient (i.e. vasodilation) across pre-exercise passive cold exposure and increased CHO oxidation (P < 0.05). Participants also reached a thermally 'comfortable' level quicker in the taurine condition (P < 0.05). A 50 mg·kg-1 dose of taurine did not statistically benefit endurance exercise after moderate cold exposure but conferred some potential vascular and metabolic effects.

Predictors of Treatment Response to Progressive Resistance Training for Adolescents With Cerebral Palsy.

OBJECTIVE: The aim of the study was to examine the variability in plantar-flexor muscle strength changes after progressive resistance training for adolescents with cerebral palsy (CP) and to identify baseline variables associated with change in muscle strength. METHODS: Thirty-three adolescents with CP were randomized to a 10-week progressive resistance training program as part of a randomized controlled trial (STAR trial). The associations between muscle strength at 10 weeks (n = 30 adolescents) and 22 weeks (n = 28 adolescents) and biomechanical and neuromuscular baseline characteristics, motor function, and fidelity to the program were examined with multivariable linear regression. RESULTS: Changes in plantar-flexor muscle strength from baseline ranged from -47.7% to 192.3% at 10 weeks and -54.3% to 198.4% at 22 weeks. Muscle activation was the only variable associated with change in strength at 10 weeks and 22 weeks. A model containing peak muscle activity and baseline muscle strength explained 49.1% of the variation in change in muscle strength (R2 = 0.491) at 10 weeks and 49.2% of the variation in change muscle strength at 22 weeks (R2 = 0.492). CONCLUSION: Assessing levels of muscle activation may be able to identify responders to a progressive resistance training program for adolescents with CP. These findings are a first step toward developing tools that can inform decision making in the clinical setting. IMPACT: Due to the heterogenous nature of CP, it is challenging to assess the efficacy of strength training programs in individuals with CP and to understand the variability in outcomes among participants. This study provides a better understanding of the factors that predict response to an exercise program so that resistance training can be directed to those who will potentially benefit from it. LAY SUMMARY: There is wide variability in how well young people with CP respond to resistance training. If you are a young person with CP, your physical therapist can measure the amount of gastrocnemius muscle activity you have, so as to get an indication of how well you will respond.

Patterns of Health Service Use Among Young People With Cerebral Palsy in England.

Background: Although the provision of healthcare for people with cerebral palsy (CP) is typically focussed on childhood, many people with CP require access to services periodically throughout their life. Few studies have examined patterns of health service use among young people with CP in England. Understanding patterns of use may inform future service development. Objective: To describe patterns of visits to rehabilitation and medical professionals among ambulatory young people with CP living in England, and identify factors associated with service use. Methods: Sixty-two young people with CP aged 10-19 years [mean (SD) age 13.7 (2.5) years] in Gross Motor Function Classification System (GMFCS) levels I-III reported visits to a range of health professionals, hospital admissions and visits to the emergency department over a median duration of 34 weeks (min-max: 12-34 weeks). Negative binomial models were used to examine factors associated with number of visits. Results: Physiotherapists were the most commonly used professional, with 67.7% of participants visiting a physiotherapist at least once, followed by dentists (66.1%), general practitioners (48.4%), occupational therapists (40.3%) and orthopaedic surgeons (40.3%). Physiotherapists were also the most frequently visited professional with a total of 473 visits (13.3 visits per person-year). Speech and language therapists (5.0 visits per person-year), occupational therapists (4.5 visits per person-year) and nurses (4.3 per person-year) were the next most frequently visited professionals. Age, GMFCS level, and speech impairment were associated with rate of visits to a physiotherapist. Conclusions: The proportion of young people who visited medical and rehabilitation professionals during the study period varied considerably depending on the profession. Generally, the proportion of young people using services was low. In the context of limited resources, data on service use in combination with data on unmet need, may support the reorganisation of services to maximise benefits to young people with CP.

The effects of COVID-19 restrictions on physical activity and mental health of children and young adults with physical and/or intellectual disabilities.

BACKGROUND: COVID-19 has caused unprecedented restrictions, significantly affecting the most vulnerable groups in society, such as those with a disability. OBJECTIVE: The aim of the study was to investigate the effects of COVID-19 lockdown restrictions on physical activity and mental health of children and young adults with physical and/or intellectual disabilities. METHODS: The study was a cross-sectional design. Parents/carers completed an electronic survey in the UK between June-July 2020 on behalf of their child. Through Likert scales and free-text questions, the survey asked about physical activity levels and mental health during lockdown compared to before, access to specialist facilities and equipment to aid with physical activity, and the short- and long-term concerns around ongoing lockdown restrictions. RESULTS: Generally, respondents reported negative effects of lockdown restrictions, with 61% reporting a reduction in physical activity levels and over 90% reporting a negative impact on mental health (including poorer behaviour, mood, fitness and social and learning regression). Many respondents cited a lack of access to specialist facilities, therapies and equipment as reasons for this, and raised concerns about the long-term effects of this lack of access on their child's mental health and physical activity levels. CONCLUSIONS: The survey highlights the negative impact of the COVID-19 lockdown on the physical activity levels and mental health of children and young adults with disabilities and highlights the importance of addressing the needs of the disabled community as restrictions are eased.

Leucine Supplementation Increases Muscle Strength and Volume, Reduces Inflammation, and Affects Wellbeing in Adults and Adolescents with Cerebral Palsy.

BACKGROUND: Spastic cerebral palsy (CP) is characterized by muscle weakness owing, in part, to a blunted muscle protein synthetic response. This might be normalized by long-term leucine supplementation. OBJECTIVES: The study assessed the effects of 10 wk leucine supplementation in adolescents and adults with CP. METHODS: The study was a single-center randomized controlled trial. Twenty-four participants were randomly assigned to a control group (n = 12) or a leucine group (n = 12). l-Leucine (192 mg/kg body mass) was dissolved in water and administered daily for 10 wk. The primary outcome measures of elbow flexor muscle strength and muscle volume (measured by 3D ultrasound technique) and inflammation [C-reactive protein (CRP) concentration] were assessed before and after the 10 wk, alongside the secondary outcomes of body composition (measured by CP-specific skinfold assessment), metabolic rate (measured by indirect calorimetry), and wellbeing (measured by a self-reported daily questionnaire). Data were compared via a series of 2-factor mixed ANOVAs. RESULTS: Twenty-one participants completed the intervention (control group: n = 11, mean ± SD age: 18.3 ± 2.8 y, body mass: 48.8 ± 11.9 kg, 45% male; leucine group: n = 10, age: 18.6 ± 1.7 y, body mass: 58.3 ± 20.2 kg, 70% male). After 10 wk, there was a 25.4% increase in strength (P = 0.019) and a 3.6% increase in muscle volume (P = 0.001) in the leucine group, with no changes in the control group. This was accompanied by a 59.1% reduction in CRP (P = 0.045) and improved perceptions of wellbeing (P = 0.006) in the leucine group. No changes in metabolism or body composition were observed in either group (P > 0.05). CONCLUSIONS: Improvements in muscle strength and volume with leucine supplementation might provide important functional changes for adults and adolescents with CP and could be partly explained by reduced inflammation. The improved wellbeing highlights its capacity to improve the quality of daily living. This trial was registered at clinicaltrials.gov as NCT03668548.

Muscle Activation Patterns During Variable Resistance Deadlift Training With and Without Elastic Bands.

ABSTRACT: Heelas, T, Theis, N, and Hughes, JD. Muscle activation patterns during variable resistance deadlift training with and without elastic bands. J Strength Cond Res 35(11): 3006-3011, 2021-The purpose of this study was to determine the effects of band-assisted variable resistance training on muscular activity in the lower limbs and barbell kinematics during the concentric phase of the deadlift. Fifteen resistance trained men (mean ± SD: 28.7 ± 9.3 years; 1.80 ± 0.90 m; 92.5 ± 15.1 kg) performed 6 deadlift repetitions during 4 loading conditions: 100-kg bar (no band), 80-kg bar with 20-kg band tension (B20), 75-kg bar with 25-kg band tension (B25), and 70-kg bar with 30-kg band tension (B30). Muscle activity from the medial gastrocnemius (MG), semitendinosus (ST), vastus medialis (VMO), vastus lateralis (VL), and gluteus maximus (GM) were recorded using surface electromyography during the concentric phase of the lift and expressed as a percentage of each muscle's maximal activity, recorded during a maximal isometric contraction. Barbell power and velocity were recorded using a linear position transducer. Electromyography results showed that muscle activity significantly decreased as band resistance increased in the MG and ST (p < 0.05) and progressively decreased in the GM. No changes were observed for the VMO or VL. Peak and mean bar velocity and power significantly increased as band resistance increased. Performing the deadlift with band-assisted variable resistance increases bar power and velocity, while concurrently decreasing muscle activation of the posterior chain musculature. Practitioners prescribing this exercise may wish to include additional posterior chain exercises that have been shown to elicit high levels of muscle activation.

No thermoregulatory or ergogenic effect of dietary nitrate among physically inactive males, exercising above gas exchange threshold in hot and dry conditions.

The aim of this study was to determine the effect of five days dietary nitrate (NO3-) consumption on exercise tolerance and thermoregulation during cycling in hot, dry conditions. In a double-blind, randomised crossover design, 11 healthy males participated in an exercise tolerance test (Tlim) in the heat (35°C, 28% relative humidity), cycling above the thermoneutral gas exchange threshold, after five days of dietary supplementation, with either NO3-rich beetroot juice (BR; ∼ 9.2 mmol NO3-) or placebo (PLA). Changes in plasma [NO3-] and nitrite [NO2-], core and mean skin temperatures, mean local and whole-body sweat rates, heart rate, perceptual ratings and pulmonary gas exchange were measured during exercise, alongside calorimetric estimations of thermal balance. Mean arterial pressures (MAP) were recorded pre-Tlim. There were no differences in Tlim between conditions (BR = 22.8 ± 8.1 min; Placebo = 20.7 ± 7.9 min) (P = 0.184), despite increases in plasma [NO3-] and [NO2-] (P < 0.001) and a 3.8% reduction in resting MAP (P = 0.004) in the BR condition. There were no other differences in thermoregulatory, cardio-metabolic, perceptual or calorimetric responses to the Tlim between conditions (P > 0.05). Dietary NO3- supplementation had no effect on exercise tolerance or thermoregulation in hot, dry conditions, despite reductions in resting MAP and increases in plasma [NO3-] and [NO2-]. Healthy, yet physically inactive individuals with no known impairments in vasodilatory and sudomotor function do not appear to require BR for ergogenic or thermolytic effects during exercise in the heat.

Comparison of the CHU-9D and the EQ-5D-Y instruments in children and young people with cerebral palsy: a cross-sectional study.

OBJECTIVE: To compare the performance of the EuroQol 5D youth (EQ-5D-Y) and child health utility 9D (CHU-9D) for assessing health-related quality of life (HRQoL) in children and young people (CYP) with cerebral palsy (CP). DESIGN: Cross-sectional study. SETTING: England. PARTICIPANTS: Sixty-four CYP with CP aged 10-19 years in Gross Motor Function Classification System (GMFCS) levels I-III. MAIN OUTCOME MEASURES: Missing data were examined to assess feasibility. Associations between utility values and individual dimensions on each instrument were examined to assess convergent validity. Associations between utility values and GMFCS level were examined to assess known-group differences. RESULTS: Missing data were <5% for both instruments. Twenty participants (32.3%) and 11 participants (18.0%) reported full health for the EQ-5D-Y and CHU-9D, respectively. There was poor agreement between utilities from the two instruments (intraclass correlation coefficient=0.62; 95% limits of agreement -0.58 to 0.29). Correlations between EQ-5D-Y and CHU-9D dimensions were weak to moderate (r=0.25 to 0.59). GMFCS level was associated with EQ-5D-Y utility values but not CHU-9D utility values. CONCLUSION: The EQ-5D-Y and CHU-9D are feasible measures of HRQoL in CYP with CP. However, the two instruments demonstrate poor agreement and should not be used to measure and value HRQoL in CYP with CP interchangeably. We propose that the CHU-9D may be preferable to use in this population as it assesses concepts that influence HRQoL among CYP with CP and provides less extreme utility values than the EQ-5D-Y.

Acute Neuromuscular Electrical Stimulation (NMES) With Blood Flow Restriction: The Effect of Restriction Pressures.

CONTEXT: Neuromuscular electrical stimulation (NMES) combined with blood flow restriction (BFR) has been shown to improve muscular strength and size better than NMES alone. However, previous studies used varied methodologies not recommended by previous NMES or BFR research. OBJECTIVE: The present study investigated the acute effects of NMES combined with varying degrees of BFR using research-recommended procedures to enhance understanding and the clinical applicability of this combination. DESIGN: Randomized crossover. SETTING: Physiology laboratory. PARTICIPANTS: A total of 20 healthy adults (age 27 [4] y; height 177 [8] cm; body mass 77 [13] kg). INTERVENTIONS: Six sessions separated by at least 7 days. The first 2 visits served as familiarization, with the experimental conditions performed in the final 4 sessions: NMES alone, NMES 40% BFR, NMES 60% BFR, and NMES 80% BFR. MAIN OUTCOME MEASURES: Maximal voluntary isometric contraction, muscle thickness, blood pressure, heart rate, rating of perceived exertion, and pain were all recorded before and after each condition. RESULTS: The NMES 80% BFR caused greater maximal voluntary isometric contraction decline than any other condition (-38.9 [22.3] N·m, P < .01). Vastus medialis and vastus lateralis muscle thickness acutely increased after all experimental conditions (P < .05). Pain and ratings of perceived exertion were higher after NMES 80% BFR compared with all other experimental conditions (P < .05). No cardiovascular effects were observed between conditions. CONCLUSION: The NMES combined with 80% BFR caused greater acute force decrement than the other conditions. However, greater perceptual ratings of pain and ratings of perceived exertion were observed with NMES 80% BFR. These acute observations must be investigated during chronic interventions to corroborate any relationship to changes in muscle strength and size in clinical populations.

Effect of RaceRunning on cardiometabolic disease risk factors and functional mobility in young people with moderate-to-severe cerebral palsy: protocol for a feasibility study.

INTRODUCTION: There is consistent evidence that people with cerebral palsy (CP) do not engage in the recommended physical activity guidelines for the general population from a young age. Participation in moderate-to-vigorous physical activity is particularly reduced in people with CP who have a moderate-to-severe disability. RaceRunning is a growing disability sport that provides an opportunity for people with moderate-to-severe disability to participate in physical activity in the community. It allows those who are unable to walk independently to propel themselves using a RaceRunning bike, which has a breastplate for support but no pedals. The aim of this study is to examine the feasibility and acceptability of RaceRunning for young people with moderate-to-severe CP and the feasibility of conducting a definitive study of the effect of RaceRunning on cardiometabolic disease risk factors and functional mobility. METHODS AND ANALYSIS: Twenty-five young people (age 5-21 years) with CP or acquired brain injury affecting coordination will be included in this single-arm intervention study. Participants will take part in one RaceRunning session each week for 24 weeks. Outcomes assessed at baseline, 12 and 24 weeks include body mass index, waist circumference, blood pressure, muscle strength, cardiorespiratory fitness, physical activity and sedentary behaviour, functional mobility, activity competence and psychosocial impact. Adverse events will be systematically recorded throughout the 24 weeks. Focus groups will be conducted with participants and/or parents to explore their views and experiences of taking part in RaceRunning. ETHICS AND DISSEMINATION: Approval has been granted by Queen Margaret University Research Ethics Committee (REC) and the South East of Scotland REC. Results will be disseminated through peer-reviewed journals and distributed to people with CP and their families through RaceRunning and Athletic Clubs, National Health Service trusts and organisations for people with disabilities. TRIAL REGISTRATION NUMBER: NCT04034342; pre-results.

Progressive resistance training for adolescents with cerebral palsy: the STAR randomized controlled trial.

AIM: To evaluate the effect of progressive resistance training of the ankle plantarflexors on gait efficiency, activity, and participation in adolescents with cerebral palsy (CP). METHOD: Sixty-four adolescents (10-19y; 27 females, 37 males; Gross Motor Function Classification System [GMFCS] levels I-III) were randomized to 30 sessions of resistance training (10 supervised and 20 unsupervised home sessions) over 10 weeks or usual care. The primary outcome was gait efficiency indicated by net nondimensional oxygen cost (NNcost). Secondary outcomes included physical activity, gross motor function, participation, muscle strength, muscle and tendon size, and muscle and tendon stiffness. Analysis was intention-to-treat. RESULTS: Median attendance at the 10 supervised sessions was 80% (range 40-100%). There was no between-group difference in NNcost at 10 (mean difference: 0.02, 95% confidence interval [CI] -0.07 to 0.11, p=0.696) or 22 weeks (mean difference: -0.08, 95% CI -0.18 to 0.03, p=0.158). There was also no evidence of between-group differences in secondary outcomes at 10 or 22 weeks. There were 123 adverse events reported by 27 participants in the resistance training group. INTERPRETATION: We found that 10 supervised sessions and 20 home sessions of progressive resistance training of the ankle plantarflexors did not improve gait efficiency, muscle strength, activity, participation, or any biomechanical outcome among adolescents with CP. WHAT THIS PAPER ADDS: Thirty sessions of progressive resistance training of the ankle plantarflexors over 10 weeks did not improve gait efficiency among ambulatory adolescents with cerebral palsy. Resistance training did not improve muscle strength, activity, or participation. Ninety percent of participants experienced an adverse event. Most adverse events were expected and no serious adverse events were reported.

Validity of the International Physical Activity Questionnaire Short Form (IPAQ-SF) as a measure of physical activity (PA) in young people with cerebral palsy: A cross-sectional study.

OBJECTIVES: The aim of this study was to examine the validity of the International Physical Activity Questionnaire Short Form (IPAQ-SF) as a measure of physical activity (PA) in young people with cerebral palsy (CP). DESIGN: Cross-sectional. SETTING: Participants were recruited through 8 National Health Service (NHS) trusts, one school, one university and through organisations that provide services for people with disabilities in England. PARTICIPANTS: Sixty-four, ambulatory young people aged 10-19 years with CP [Gross Motor Function Classification System (GMFCS) levels I-III] participated in this study. MAIN OUTCOME MEASURE: The IPAQ-SF was administered to participants. Participants were then asked to wear a wGT3X-BT triaxial accelerometer (ActiGraph, Pensacola, FL) for 7 days to objectively assess PA. Time spent in sedentary behaviour, in moderate to vigorous PA (MVPA) and in total PA (TPA) was compared between measures. RESULTS: Young people with CP self-reported less time in sedentary behaviour and underestimated the time spent in TPA, when compared to accelerometer measurements. Bland-Altman plots demonstrated poor agreement between the measures for MVPA, with upper and lower 95% limits of agreement of -147 to 148.9minute. After adjusting for gender and GMFCS level, age was a predictor of the difference between measures for MVPA (P<0.001) and TPA (P<0.001). CONCLUSIONS: These findings suggest that the IPAQ-SF is not a valid method of measuring TPA or sedentary behaviour in young people with CP and it is not appropriate for use when assessing an individual's time in MVPA. Therefore, where feasible, an objective measure of PA should be used. CLINICAL TRIAL REGISTRATION NUMBER: ISRCTN90378161.

Absolute and Allometrically Scaled Lower-Limb Strength Differences Between Children With Overweight/Obesity and Typical Weight Children.

Theis, N, Le Warne, M, Morrison, SC, Drechsler, W, and Mahaffey, R. Absolute and allometrically scaled lower-limb strength differences between children with overweight/obesity and typical weight children. J Strength Cond Res 33(12): 3276-3283, 2019-The purpose of this study was to compare isometric and isokinetic hip, knee, and ankle strength in children with overweight/obesity (OWB) and typical weight (TW) of age 6-12 years. Absolute torque and torque allometrically scaled to body mass and fat-free mass were derived to allow for comparison of strength irrespective of body size. Using a cross-sectional design, 26 OWB (body mass index [BMI] Z score: 2.28 ± 0.77, 54% females) children were matched in age and height with 26 TW (BMI Z score: -0.39 ± 0.96, 54% females). Subjects performed maximal isometric and isokinetic contractions in ankle dorsiflexion and plantarflexion, knee flexion and extension, hip flexion and extension, and isometric hip abduction and adduction. Between-group differences in absolute and normalized isometric and isokinetic strength were compared with 1-way analysis of variances. Statistical significance was set at p < 0.05. Children with OWB had significantly greater absolute torque in the knee flexors and extensors (15-21%) and greater isokinetic ankle dorsiflexion (8%) but lower isometric hip abduction (21%) compared with TW children. When strength was allometrically scaled to body mass, children with OWB were significantly weaker at the ankle (19-25%), hip (21-36%), and in the knee extensors (12-15%). When torque was allometrically scaled to fat-free mass, children in the OWB group had greater knee flexor and extensor strength (12-14%) but were weaker in isometric hip abduction (33%) and isokinetic hip flexion and extension (29-40%). The results demonstrated that deficits in strength, relative to body mass, at the ankle and hip may be greater than those of the knee. These strength deficits in the group with OWB highlight the need for targeted musculoskeletal strength interventions to incorporate all lower-limb muscle groups.

Predictors of Walking Efficiency in Children With Cerebral Palsy: Lower-Body Joint Angles, Moments, and Power.

BACKGROUND: People with cerebral palsy (CP) experience increased muscle stiffness, muscle weakness, and reduced joint range of motion. This can lead to an abnormal pattern of gait, which can increase the energy cost of walking and contribute to reduced participation in physical activity. OBJECTIVE: The aim of the study was to examine associations between lower-body joint angles, moments, power, and walking efficiency in adolescents with CP. DESIGN: This was a cross-sectional study. METHODS: Sixty-four adolescents aged 10 to 19 years with CP were recruited. Walking efficiency was measured as the net nondimensional oxygen cost (NNcost) during 6 minutes of overground walking at self-selected speed. Lower-body kinematics and kinetics during walking were collected with 3-dimensional motion analysis, synchronized with a treadmill with integrated force plates. The associations between the kinematics, kinetics, and NNcost were examined with multivariable linear regression. RESULTS: After adjusting for age, sex, and Gross Motor Function Classification System level, maximum knee extension angle (ß = -0.006), hip angle at midstance (ß = -0.007), and maximum hip extension (ß = -0.008) were associated with NNcost. Age was a significant modifier of the association between the NNcost and a number of kinematic variables. LIMITATIONS: This study examined kinetic and kinematic variables in the sagittal plane only. A high interindividual variation in gait pattern could have influenced the results. CONCLUSIONS: Reduced knee and hip joint extension are associated with gait inefficiency in adolescents with CP. Age is a significant factor influencing associations between ankle, knee, and hip joint kinematics and gait efficiency. Therapeutic interventions should investigate ways to increase knee and hip joint extension in adolescents with CP.

Locomotor Adaptations During RaceRunning in People With Neurological Motor Disorders.

The aim of this study was to examine strategies to absorb impact shock during RaceRunning in participants with neurological motor disorders. For this purpose, 8 RaceRunning athletes (4 male and 4 female) voluntarily took part in the study. Each participant performed a series of 100-m sprints with a RaceRunning bike. Acceleration of the tibia and head was measured with 2 inertial measurement units and used to calculate foot-impact shock measures. Results showed that RaceRunning pattern was characterized by a lack of impact peak in foot-ground contact time and the existence of an active peak after foot contact. Due to the ergonomic properties of the RaceRunning bike, shock is attenuated throughout the stance phase. In conclusion, the results revealed that RaceRunning athletes with neurological motor disorders are capable of absorbing impact shock during assisted RaceRunning using a strategy that mimics runners without disabilities.

A comparison of 3D ultrasound to MRI for the measurement and estimation of gastrocnemius muscle volume in adults and young people with and without cerebral palsy.

Muscle volume (MV) is an important parameter for understanding muscle morphology and adaptations to training, growth and pathology. In this study, we assessed the validity of freehand 3D ultrasound (3DUS) for measuring medial gastrocnemius MV in adults, typically developing (TD) children and children with cerebral palsy (CP). We also assessed the validity between our direct measures of MV and estimates derived from anatomical cross sectional area (ACSA) and muscle length (ML), using previously outlined methods. The medial gastrocnemius of all groups was scanned with 3DUS and MRI. Images from both methods were digitized to derive MV, ACSA and ML. Measured MV was compared between methods and compared to estimated MV derived from recently published algorithms. MV had a mean difference of -0.13% (standard error of estimate (SEE) = 2.23%, R2 = 0.99) between MRI and 3DUS and 19.82% (SEE = 4.73% and R2 = 0.99) and -3.11% (SEE = 6.55%, R2 = 0.99) mean differences between the measured and estimated MV from two methods of estimation. The 3DUS is a valid method for the measurement of MV in adults, TD children and those with CP. Estimation methods of MV may be useful in clinical practice, but require further replication on various populations and careful methodological consideration. Clin. Anat. 32:319-327, 2019. © 2018 Wiley Periodicals, Inc.