Understanding skeletal muscle in cerebral palsy: a path to personalized medicine?

Until recently, there has been little interest in understanding the intrinsic features associated with the pathomorphology of skeletal muscle in cerebral palsy (CP). Coupled with emerging evidence that challenges the role of spasticity as a determinant of gross motor function and in the development of fixed muscle contractures, it has become increasingly important to further elucidate the underlying mechanisms responsible for muscle alterations in CP. This knowledge can help clinicians to understand and apply treatment modalities that take these aspects into account. Thus, the inherent heterogeneity of the CP phenotype allows for the potential of personalized medicine through the understanding of muscle pathomorphology on an individual basis and tailoring treatment approaches accordingly. This review aims to summarize recent developments in the understanding of CP muscle and their relationship to musculoskeletal manifestations, in addition to proposing a treatment paradigm that incorporates this new knowledge.

Acquisition and loss of best walking skills in children and young people with bilateral cerebral palsy.

AIM: To explore factors predicting acquisition and loss of best walking ability in young people with bilateral cerebral palsy (CP). METHOD: In our population cohort (Study of Hips And Physical Experience) of 338 children (201 males, 137 females) with bilateral CP, age at achieving walking was recorded and walking ability predicted from early motor milestones. Walking was assessed at 5 to 8 years (mean 7y) and in 228 of 278 survivors at 13 to 19 years (mean 16y). Parent carers reported their view of any loss of best achieved walking. Factors potentially associated with loss of best achieved walking were explored: severity and type of motor disorder; intellect and communication; manipulative skill; general health and comorbidity; pain; orthopaedic surgery; musculoskeletal spine and lower limb deformity; weight; fatigue; mood; and presence of regular exercise regime. RESULTS: The ability to walk independently was reliably predicted by the motor milestone 'getting to sit and maintain sitting' by the age of 36 months (without aids) and 55 months (with aids). Forty-five per cent of the cohort never walked 10 steps independently. Not all who achieved walking without aids were still doing so by a mean age of 16 years, which was associated with later age at achieving walking and the degree of musculoskeletal deformity, as was the parent carers' report of loss of best walking. INTERPRETATION: In this study, development of musculoskeletal deformity was a significant factor in not maintaining best achieved walking by mean age 16 years, which is most likely to occur in young people whose walking ability is with aids over short distances or in therapy only. Prediction of future walking ability in a child with bilateral CP can be made from early motor milestones.

Clinicians' Experiences of Instrumented Gait Analysis in Management of Patients with Cerebral Palsy: A Qualitative Study.

AIM: To identify the interaction of instrumented gait analysis (IGA) training, expertise, and application in gait-related management of cerebral palsy. METHODS: Semi-structured interviews with 20 purposively sampled clinicians with varying professional backgrounds, expertise, and training, analyzed using the framework method. RESULTS: Fifteen sub-themes were identified within three domains: training, equipment/outputs, and roles/reasons under the core theme IGA practice. Findings were illustrated using the Experience/Equipment/Roles/Training (Exp-ERT) Framework which identifies four user categories - based on influencing factors, beset by barriers, with experience reported as a common enabling factor. Clinicians who encountered barriers in one of the domains were categorized as either "frustrated" or "hesitant" users. Those who were no longer using IGA for clinical decisions were designated "confident non-users". Finally, the 'confident experts' reported the required level of training and access to interpret IGA outputs for clinical decision-making. Expertise gained at any level of clinical practice was shown to initiate advancement within domains. CONCLUSIONS: Clinicians encounter a multitude of barriers to IGA practice that can result in failure to progress or impact on clinical decision-making. The Exp-ERT Framework emerges strongly from the data and could serve as an evaluation tool to diagnose barriers to confident expertise and support IGA-related professional development planning.

3D ultrasound to quantify lateral hip displacement in children with cerebral palsy: a validation study.

AIM: To assess the validity of a new index, lateral head coverage (LHC), for describing hip dysplasia in a population of children with cerebral palsy (CP). METHOD: LHC is derived from 3D ultrasound assessment. Twenty-two children (15 males, seven females; age 4-15y) with CP undergoing routine hip surveillance were recruited prospectively for the study. Each participant had both a planar radiograph acquired as part of their routine care and a 3D ultrasound assessment within 2 months. Reimer's migration percentage (RMP) and LHC were measured by the same assessor, and the correlation between them calculated using Pearson's correlation coefficient. The repeatability of LHC was investigated with three assessors, analysing each of 10 images three times. Inter- and intra-assessor variation was quantified using intraclass correlation coefficients. RESULTS: LHC was strongly correlated with RMP (Spearman's rank correlation coefficient=-0.86, p<0.001). LHC had similar inter-assessor reliability to that reported for RMP (intraclass correlation coefficient=0.97 and intra-assessor intraclass correlation coefficient=0.98). INTERPRETATION: This is an initial validation of the use of 3D ultrasound in monitoring hip development in children with CP. LHC is comparable with RMP in estimating hip dysplasia with similar levels of reliability that are reported for RMP.

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.

Selective motor control and gross motor function in bilateral spastic cerebral palsy.

AIM: To investigate the relationship between selective motor control (SMC), muscle volume, and spasticity with gross motor function in adolescents and young adults with bilateral spastic cerebral palsy (CP). METHOD: Eleven male participants with CP (mean age 15y 7mo, standard deviation 3y 6mo, range 12y 1mo-23y 1mo) in Gross Motor Function Classification System (GMFCS) levels I to IV took part in this cross-sectional study. Magnetic resonance imaging (MRI) of both lower limbs of all participants were acquired, from which 18 muscles were manually segmented and muscle volume calculated by a single assessor. Muscle volumes were normalized to body mass and averaged between limbs for each individual. SMC was assessed using Selective Control Assessment of the Lower Extremity (SCALE). Spasticity was assessed using the Modified Ashworth Scale (MAS), and gross motor functional ability was assessed using the Gross Motor Function Measure (GMFM-66). RESULTS: GMFM-66 was strongly positively correlated to SCALE (r=0.901, p≤0.001) and lower limb muscle volume normalized to body mass (r=0.750, p=0.008). MAS was significantly correlated with GMFM-66 (r=-0.691, p=0.018). INTERPRETATION: SMC is a major factor influencing gross motor function in individuals with CP. Lower limb muscle volume and spasticity also influence gross motor function. WHAT THIS PAPER ADDS: Selective motor control is a major factor of gross motor function in adolescents and young adults with bilateral cerebral palsy (CP). Gross motor function is related to muscle size and level of spasticity in adolescents and young adults with bilateral CP.

Factors associated with pain in adolescents with bilateral cerebral palsy.

AIM: We explored factors associated with pain and its severity in a population cohort of young people with bilateral cerebral palsy, comparing parent/carer and young people self-reports. METHOD: Of 278 survivors (mean age 16y 8mo, SD 1y 4mo, range 13y 8mo-19y 3mo) from the South Thames in the Study of Hips and Physical Experience cohort of 338 young people with bilateral cerebral palsy, 212 parents/carers and 153 young people completed questionnaires on the presence, severity, timing, site, associated factors, impact, and treatment of pain. RESULTS: Seventy per cent of parents/carers reported pain within 3 months, 59% the previous week, and 50% the previous day with 56% reporting 'regularly experienced'. Of young people able to do so, 63% reported pain within 3 months, 50% the previous week, and 42% the previous day, with 48% reporting regular pain. There was strong agreement between the parent/carer and young people, reporting pain severity over the previous 3 months. Pain severity was associated with increased motor impairment and comorbidity, particularly constipation, spasticity, equipment use, and higher emotional score, but not sex, intellectual disability, speech, or maternal education. Multiple sites of musculoskeletal pain were reported in two-thirds of individuals. Pain was associated with voluntary movement in individuals with less motor impairment and with being moved in those with severe motor impairment. Greater pain severity had a negative effect on both physical and psychological quality of life. INTERPRETATION: Increasing awareness of the comorbidities in cerebral palsy may aid effective treatment, reducing pain experienced by young people with cerebral palsy. WHAT THIS STUDY ADDS: Regular moderate or severe pain is reported in young people with bilateral cerebral palsy (CP) in all Gross Motor Function Classification System levels. Pain is reported more frequently in young people who are non-ambulant. General ill health is strongly associated with severity of pain after controlling for severity of CP, especially constipation. Pain occurs most often in ambulant young people during voluntary activity and in those who are non-ambulant when being moved. There is strong agreement between parents/carers and young people about pain presence and severity.

FACTORES ASOCIADOS AL DOLOR EN ADOLESCENTES CON PARÁLISIS CEREBRAL BILATERAL: OBJETIVO: Exploramos los factores asociados con el dolor y su gravedad en una cohorte poblacional de jóvenes con parálisis cerebral bilateral, comparando los autoinformes de padres/cuidadores y jóvenes. MÉTODO: De 278 sobrevivientes (edad media 16 años 8 meses, DS 1 año 4 meses, rango 13 años 8 meses - 19 años 3 meses) del Támesis Meridional, en el Estudio de caderas y experiencia física de 338 jóvenes con parálisis cerebral bilateral, 212 padres/cuidadores y 153 los jóvenes completaron cuestionarios sobre la presencia, la gravedad, el momento, el sitio, los factores asociados, el impacto y el tratamiento del dolor. RESULTADOS: El 70% de los padres/cuidadores reportaron dolor dentro de los 3 meses, el 59% en la semana anterior y el 50% en el día anterior, y el 56% informaron tener dolor "como experiencia regular". De los jóvenes que pueden hacerlo, 63% reportaron dolor dentro de los 3 meses, 50% la semana anterior y 42% el día anterior, con 48% reportando dolor regular. Hubo un fuerte acuerdo entre los padres/cuidadores y los jóvenes, que informaron sobre la gravedad del dolor durante los 3 meses anteriores. La gravedad del dolor se asoció con un aumento del deterioro motor y la comorbilidad, en particular el estreñimiento, la espasticidad, el uso de equipos y una mayor puntuación emocional, pero no el sexo, la discapacidad intelectual, el habla o la educación materna. Se reportaron múltiples sitios de dolor musculoesquelético en dos tercios de los individuos. El dolor se asoció con el movimiento voluntario en individuos con menos discapacidad motora y con el traslado en personas con insuficiencia motora grave. Una mayor gravedad del dolor tuvo un efecto negativo en la calidad de vida tanto física como psicológica. INTERPRETACIÓN: Un mayor conocimiento de las comorbilidades en la parálisis cerebral puede ayudar a un tratamiento eficaz, reduciendo el dolor que experimentan los jóvenes con parálisis cerebral.

FATORES ASSOCIADOS COM DOR EM ADOLESCENTES COM PARALISIA CEREBRAL BILATERAL: OBJETIVO: Exploramos os fatores associados com dor e sua severidade em uma coorte de jovens com paralisia cerebral bilateral, comparando auto-relatos dos jovens e relatos dos pais/cuidadores. MÉTODO: Dos 278 sobreviventes (média de idade 16a 8m, DP 1a 4m, variação 13a 8m-19a 3m) de South Thames, da coorte de 228 jovens com paralisia cerebral bilateral do Estudo dos Quadris e Experiência Física, 212 pais/cuidadores e 153 jovens completaram os questionários de presença, severidade, momento, local, fatores associados, impacto, e tratamento da dor. RESULTADOS: Setenta por cento dos pais/cuidadores relataram dor em 3 meses, 59% na semana anterior, e 50% no dia anterior, com 56% indicando "sente regularmente". Dos jovens capazes de fazê-lo, 63% reportaram dor em 3 meses, 50% na última semana, e 42% no dia anterior, com 48% reportando dor regular. Houve forte concordância entre pais/cuidadores e jovens, relatando severidade da dor nos 3 meses anteriores. A severidade da dor se associou com maior comprometimento motor e comorbidades, particularmente constipação, espasticidade, uso de equipamentos, e maior pontuação emocional, mas não com o sexo, deficiência intelectual, fala, ou educação materna. Múltiplos locais de dor músculo-esquelética foram relatados em dois terços dos indivíduos. A dor foi associada com movimento voluntário em indivíduos com menor comprometimento motor, e com ser movido naqueles com comprometimento severo. Maior severidade da dor teve efeito negativo tanto na qualidade de vida física e psicológica. INTERPRETAÇÃO: Aumentar a conscientização sobre as comorbidades em paralisia cerebral pode ajudar tratamentos efetivos, reduzindo a dor sentida por jovens com paralisia cerebral.

Reliability and feasibility of gait initiation centre-of-pressure excursions using a Wii® Balance Board in older adults at risk of falling.

BACKGROUND: Impairments in dynamic balance have a detrimental effect in older adults at risk of falls (OARF). Gait initiation (GI) is a challenging transitional movement. Centre of pressure (COP) excursions using force plates have been used to measure GI performance. The Nintendo Wii Balance Board (WBB) offers an alternative to a standard force plate for the measurement of CoP excursion. AIMS: To determine the reliability of COP excursions using the WBB, and its feasibility within a 4-week strength and balance intervention (SBI) treating OARF. METHODS: Ten OARF subjects attending SBI and ten young healthy adults, each performed three GI trials after 10 s of quiet stance from a standardised foot position (shoulder width) before walking forward 3 m to pick up an object. Averaged COP mediolateral (ML) and anteroposterior (AP) excursions (distance) and path-length time (GI-onset to first toe-off) were analysed. RESULTS: WBB ML (0.866) and AP COP excursion (0.895) reliability (ICC3,1) was excellent, and COP path-length reliability was fair (0.517). Compared to OARF, healthy subjects presented with larger COP excursion in both directions and shorter COP path length. OARF subjects meaningfully improved their timed-up-and-go and ML COP excursion between weeks 1-4, while AP COP excursions, path length, and confidence-in-balance remained stable. DISCUSSION: COP path length and excursion directions probably measure different GI postural control attributes. Limitations in WBB accuracy and precision in transition tasks needs to be established before it can be used clinically to measure postural aspects of GI viably. CONCLUSIONS: The WBB could provide valuable clinical evaluation of balance function in OARF.

Author Correction: Reliability and feasibility of gait initiation centre-of-pressure excursions using a Wii® Balance Board in older adults at risk of falling.

In the original publication, the article title was incorrectly published as 'Reliability and feasibility of gait initiation centre-of-pressure excursions using a Wii® Balance Board in older adults at risk of failing'. The correct title should read as 'Reliability and feasibility of gait initiation centre-of-pressure excursions using a Wii® Balance Board in older adults at risk of falling'.

The relationship between lower limb muscle volume and body mass in ambulant individuals with bilateral cerebral palsy.

BACKGROUND: Individuals with cerebral palsy have smaller muscle volumes normalised to body mass than their typically developing peers. The aim of this study is to investigate the relationship between lower limb muscle volume and body mass in young people with bilateral cerebral palsy and their typically developing peers. METHODS: Twenty-five participants with bilateral cerebral palsy (aged 14.7±3.0 years, GMFCS level I-III) and 25 of their typically developing peers (aged 16.8±3.3 years) took part in this study. None of the participants had undergone orthopaedic surgery, botulinum toxin injections, or serial casting in the previous year. All participants underwent magnetic resonance imaging of both lower limbs. Nine major muscles of each lower limb were individually manually segmented and the muscle volumes calculated. RESULTS: Body mass and total lower limb muscle volume were significantly linearly related in both the cerebral palsy (R2 = 0.75, p<0.001) and typically developing (R2 = 0.77, p<0.001) groups. The slope of the relationship between muscle volume and body mass was significantly shallower in the cerebral palsy group compared to the typically developing group (p=0.007). CONCLUSIONS: This cross-sectional study suggests that the increase in size of lower limb muscles relative to body mass is reduced in adolescents and young adults with cerebral palsy. Longitudinal studies are required to further investigate altered muscle growth trajectories in this group and their impact on long-term mobility.

An assessment of the physical impact of complex surgical tasks on surgeon errors and discomfort: a comparison between robot-assisted, laparoscopic and open approaches.

OBJECTIVES: To evaluate, in a simulated suturing task, individual surgeons' performance using three surgical approaches: open, laparoscopic and robot-assisted. subjects and methods: Six urological surgeons made an in vitro simulated vesico-urethral anastomosis. All surgeons performed the simulated suturing task using all three surgical approaches (open, laparoscopic and robot-assisted). The time taken to perform each task was recorded. Participants were evaluated for perceived discomfort using the self-reporting Borg scale. Errors made by surgeons were quantified by studying the video recording of the tasks. Anastomosis quality was quantified using scores for knot security, symmetry of suture, position of suture and apposition of anastomosis. RESULTS: The time taken to complete the task by the laparoscopic approach was on average 221 s, compared with 55 s for the open approach and 116 s for the robot-assisted approach (anova, P < 0.005). The number of errors and the level of self-reported discomfort were highest for the laparoscopic approach (anova, P < 0.005). Limitations of the present study include the small sample size and variation in prior surgical experience of the participants. CONCLUSIONS: In an in vitro model of anastomosis surgery, robot-assisted surgery combines the accuracy of open surgery while causing lesser surgeon discomfort than laparoscopy and maintaining minimal access.

Intramuscular fat in ambulant young adults with bilateral spastic cerebral palsy.

BACKGROUND: It is known that individuals with bilateral spastic cerebral palsy (BSCP) have small and weak muscles. However, no studies to date have investigated intramuscular fat infiltration in this group. The objective of this study is to determine whether adults with BSCP have greater adiposity in and around their skeletal muscles than their typically developing (TD) peers as this may have significant functional and cardio-metabolic implications for this patient group. METHODS: 10 young adults with BSCP (7 male, mean age 22.5 years, Gross Motor Function Classification System (GMFCS) levels I-III), and 10 TD young adults (6 male, mean age 22.8 years) took part in this study. 11 cm sections of the left leg of all subjects were imaged using multi-echo gradient echo chemical shift imaging (mDixon). Percentage intermuscular fat (IMAT), intramuscular fat (IntraMF) and a subcutaneous fat to muscle volume ratio (SF/M) were calculated. RESULTS: IntraMF was higher with BSCP for all muscles (p = 0.001-0.013) and was significantly different between GMFCS levels (p < 0.001), with GMFCS level III having the highest IntraMF content. IMAT was also higher with BSCP p < 0.001). No significant difference was observed in SF/M between groups. CONCLUSION: Young adults with BSCP have increased intermuscular and intramuscular fat compared to their TD peers. The relationship between these findings and potential cardio-metabolic and functional sequelae are yet to be investigated.

Can on-line gait training improve clinical practice? Study protocol for feasibility randomised controlled trial of an on-line educational intervention to improve clinician's gait-related decision-making in ambulant children and young people with cerebral palsy.

BACKGROUND: Instrumented gait analysis (IGA) is an assessment and research tool with proven impacts on clinical decision-making for the management of ambulant children and young people with cerebral palsy (CYPwCP) but is underused and variably understood by relevant clinicians. Clinicians' difficulties in gaining expertise and confidence in using IGA are multifactorial and related to access for clinical decision-making, limited training opportunities and inability to translate this training into clinical practice. METHODS: The primary aim of this study is to test the feasibility of an educational intervention to advance clinicians' application of gait analysis in CYPwCP, to inform a definitive trial. The secondary aim is to measure the effect that appropriate IGA training has on physiotherapists' knowledge, skills, confidence and behaviours. This will be a two-arm feasibility randomised controlled trial with an experimental and control group. The 6-week on-line intervention uses a multicomponent approach grounded in behavioural change techniques. A repeated measures design will be adopted, whereby participants will complete outcome measures at baseline, immediately after the intervention and at 4 months. The primary outcome measures (trial feasibility-related outcomes) are recruitment and engagement. The secondary outcome measures (trial research-related outcomes) are knowledge, skills, confidence and practice change. Outcome measures will be collected via online questionnaires and during observed skill assessments. Analysis of data will use descriptive statistics, two-way mixed ANOVA model and qualitative content analysis. DISCUSSION: This study will determine feasibility of the definitive randomised control trial of educational intervention delivered to advance clinicians' application of gait analysis in CYPwCP. This study offers the shift in emphasis from regarding IGA as a tool to a focus on clinicians' requirements for access, training and a well-defined role to optimise utilisation of IGA. The impact of this should be better engagement with IGA and clinical practice change. This study will contribute to a body of educational research into clinical education of healthcare professionals and IGA training offering insight into high levels of evaluation evidence including clinical behaviour change. TRIAL REGISTRATION: Protocol has been registered with the Open Science Framework (osf.io/nweq6) in June 2023.

The impact of instrumented gait analysis on decision-making in the interprofessional management of cerebral palsy: A scoping review.

BACKGROUND: Management of gait-related problems in children and young people with Cerebral Palsy (CYPwCP) is complex and requires an interprofessional approach. Irrespective of underlying mechanisms, instrumented gait analysis (IGA) can provide quantification of gait to support clinical decision-making for CYPwCP when planning treatment interventions. AIM: This scoping review aimed to determine the impact of instrumented gait analysis (IGA) on treatment decision-making for CYPwCP, paying particular attention to interprofessional decision-making. METHOD: PubMed, EMBASE, Web of Science and Scopus databases were searched from inception to October 2019 for studies including CYPwCP age<25 years. The PRISMA ScR protocol was followed, and Quality was assessed with the Downs and Black (D&B) scale. Influences on decision-making were coded according to the International Classification of Functioning, Disability and Health for Children and Youth framework (ICF-CY). RESULTS: Seventeen studies (1144 patients, 2.8-23 years) of varying quality (mean D&B = 17.2, range = 11-26) were included. Studies considered IGA influence at three decision-making stages 'Clinical Planning', 'Treatment Performed' and 'Follow up'. Child and Family, and Clinician and Service-centred factors had a high impact on engagement with IGA recommendations. INTERPRETATION: IGA guided recommendations can differ from initial clinical plans, and often lead to modification of the treatment ultimately performed. The effect on individual patients' outcomes when treatment recommendations based on instrumented gait analysis are followed is not yet clear and warrants further research. The differences in clinicians' engagement with IGA recommendations occur due to an array of Child and Family, and Clinician and Service-centred factors. Overall, IGA leads to less surgical recommendations, and has the potential to influence conservative gait-related management in CYPwCP.

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.

Could muscle deformity in children with spastic cerebral palsy be related to an impairment of muscle growth and altered adaptation?

Skeletal muscle deformity is common in children with spastic cerebral palsy (CP), but the underlying mechanisms are unclear. This review explores some possible factors which may influence the development of muscle deformity in CP. Normal muscle function and growth appear to depend on the interaction of neuronal, endocrinal, nutritional, and mechanical factors, and also on the development of an appropriate balance between muscle protein synthesis and degradation, and between the development of contractile and non-contractile components. In this context, the changes seen in muscle in children with CP are reviewed and discussed. It is suggested that the development of muscle deformity in children with CP may be related to a multifactorial impairment of muscle growth, on which adaptation of the extracellular matrix due to altered loading may be imposed.

Does delayed onset muscle soreness affect the biomechanical variables of the drop vertical jump that have been associated with increased ACL injury risk? A randomised control trial.

INTRODUCTION: Delayed onset muscle soreness (DOMS) and Anterior Cruciate Ligament (ACL) injuries are both prevalent in sport. It is currently unknown whether DOMS increases ACL injury risk. AIM: This study aimed to provide preliminary insight on whether DOMS affects ACL injury risk by investigating whether DOMS affects the biomechanical variables of the DVJ that have been identified as risk factors for future ACL injury. METHODS: This was a randomised control trial involving 32 active individuals aged 18-35 years, with no history of ACL injury. Participants underwent two sessions of force-plate testing and 3D motion analysis of the drop vertical jump (DVJ). The DVJ was chosen as it has been investigated prospectively for association with future ACL injury. Initial testing was followed by randomisation to DOMS or control group. The DOMS group underwent a DOMS-inducing exercise protocol, the control group did not. Both groups were re-tested 48 h after initial testing. Five variables of the DVJ that have been associated with future ACL injury were chosen for analysis - peak knee flexion angle, peak vertical ground reaction force, ground contact time, peak knee abduction angle & peak knee abduction moment. Between-group differences were compared using a two-way mixed analysis of variance; alpha level set to 0.05. RESULTS: DOMS was successfully induced in all participants of the DOMS group however no statistically significant group x time interactions were found for any of the five variables analysed. CONCLUSIONS: DOMS did not affect the biomechanical variables of the DVJ that have been associated with future ACL injury. By extension, this may suggest that DOMS might not affect ACL injury risk. However, it is also possible that certain attributes of the DVJ meant that any effect of DOMS was simply unable to be quantified, even if an effect existed. All considered, our position is that conclusion cannot be drawn from this study alone on whether DOMS affects ACL injury risk. Further research is required.