Short-Term Muscle Power Is Related to Lower Limb Muscle Volume in Young Children.

PURPOSE: Muscle power is a component of muscular fitness and is proportional to its volume. Reduced muscular fitness in children is linked to negative health outcomes. Associations between muscle volume (MV) and power have not been examined in young children and could reveal important insights into early neuromuscular development. METHOD: Forty-four children (2-8 y) completed 3 tests of short-term muscular power: repeated anaerobic sprint test, vertical jump, and horizontal jump. MV was assessed using 3D ultrasound for 3 lower limb muscles (rectus femoris, medial gastrocnemius, and tibialis anterior) and summed for across legs. Associations between muscular power and summed MV were assessed using Pearson correlation (r). Sex-based differences in muscular power and MV were assessed using 1-way analysis of covariance. RESULTS: Moderate-strong associations (r = .57 - .87) were found between muscular power and summed MV. No differences were found between boys and girls for height, weight, MV, or muscular power. CONCLUSIONS: Young children who have larger lower limb muscles perform better at tasks dependent on short-term muscular power, such as running and jumping, compared with children with smaller muscles. Sex-based differences in short-term muscular power do not exist in young children and reflect similar anthropometry, including lower limb MV.

Medial gastrocnemius growth in children who are typically developing: Can changes in muscle volume and length be accurately predicted from age?

Muscle size is an important determinant of muscular fitness and health, and so it is important to have accurate estimates of actual muscle growth in children. This study compared actual versus age-predicted growth rates of the medial gastrocnemius (MG) muscle in young children over a 12-month period. Three-dimensional ultrasound was used to measure MG length and volume in 50 children (mean ± standard deviation [SD] age = 70.3 ± 29.9 months) to establish age-predicted muscle growth rates using a least-squares linear regression. Twenty children (mean ± SD age = 78.5 ± 27.2 months) were followed up at 6 and 12 months to establish actual muscle growth of MG volume and length. These data were then compared to their age-predicted muscle growth from the linear regression equation using paired t-tests and Bland-Altman limits of agreement method. Age-predicted MG growth significantly underestimated actual muscle growth for both volume and length at each timepoint. On average, actual muscle volume and length were 11.5% and 21.5% greater than the age-predicted volume and length respectively. Caution is warranted when predicting future muscle size in young children based solely on age.

Plantar flexor voluntary activation capacity, strength and function in cerebral palsy.

PURPOSE: Distal lower limb motor impairment impacts gait mechanics in individuals with cerebral palsy (CP), however, the contribution of impairments of muscle activation to reduced gross motor function (GMF) is not clear. This study aimed to investigate deficits in plantar flexion voluntary activation capacity in CP compared to typically developed (TD) peers, and evaluate relationships between voluntary activation capacity, strength and GMF. METHODS: Fifteen ambulant individuals with spastic CP (23 ± 6 years, GMFCS I-III) and 14 TD (22 ± 2 years) people participated. Plantar- and dorsiflexion strength were assessed with a dynamometer. Voluntary activation capacity was assessed using the interpolated twitch technique via single twitch supramaximal tibial nerve stimulation. GMF was assessed using the timed upstairs test, 10 m walk test, muscle power sprint test and six-minute walk test. RESULTS: Plantar- and dorsiflexion strength were 55.6% and 60.7% lower in CP than TD (p < 0.001). Although voluntary activation capacity was 17.9% lower on average for CP than TD (p = 0.039), 46.7% of individuals with CP achieved a sufficiently high activation to fall within one standard deviation of the TD mean. Plantar flexion voluntary activation capacity did not correlate with strength (R2 = 0.092, p = 0.314) or GMF measures in the high functioning CP group (GMFCS I-II). CONCLUSION: In contrast to previous research, plantar flexion activation capacity did not strongly predict weakness or reduced GMF. We propose that muscle size contributes more to weakness than voluntary activation capacity in high functioning individuals with CP and that relationships between muscle activation and functional capacity are complicated by effects at multiple joints.

Characterization of torque generating properties of ankle plantar flexor muscles in ambulant adults with cerebral palsy.

PURPOSE: Weakness of plantar flexor muscles is related to reduced push-off and forward propulsion during gait in persons with cerebral palsy (CP). It has not been clarified to what an extent altered muscle contractile properties contribute to this muscle weakness. Here, we investigated the torque generating capacity and muscle fascicle length in the triceps surae muscle throughout ankle range of motion (ROM) in adults with CP using maximal single muscle twitches elicited by electrical nerve stimulation and ultrasonography. METHODS: Fourteen adults with CP (age 36, SD 10.6, GMFCS I-III) and 17 neurological intact (NI) adults (age 36, SD 4.5) participated. Plantar flexor torque during supramaximal stimulation of the tibial nerve was recorded in a dynamometer at 8 ankle angles throughout ROM. Medial gastrocnemius (MG) fascicle length was tracked using ultrasonography. RESULTS: Adults with CP showed reduced plantar flexor torque and fascicle shortening during supramaximal stimulation throughout ROM. The largest torque generation was observed at the ankle joint position where the largest shortening of MG fascicles was observed in both groups. This was at a more plantarflexed position in the CP group. CONCLUSION: Reduced torque and fascicle shortening during supramaximal stimulation of the tibial nerve indicate impaired contractile properties of plantar flexor muscles in adults with CP. Maximal torque was observed at a more plantarflexed position in adults with CP indicating an altered torque-fascicle length/ankle angle relation. The findings suggest that gait rehabilitation in adults with CP may require special focus on improvement of muscle contractility.

The effect of deloading tape on medial gastrocnemius muscle fascicle behaviour during dynamic exercise.

This study examined the effect of diamond deloading tape on medial gastrocnemius (MG) muscle behaviour during exercise in healthy adults (n = 27). A randomised cross-over trial assessed the effect of tape (no-tape, sham-tape and deload-tape) on ankle and MG fascicle kinematics during three heel raise-lower exercises [double leg (DL), single leg (SL) and loaded single leg (LSL)]. There was no effect of tape on standing fascicle length (FL) or pennation angle (PA), or ankle or knee joint angle. There was a significant effect of tape on ankle kinematics for all exercises. Both the deload-tape and sham-tape resulted in less ankle plantar flexion but had no effect on dorsiflexion. There was a significant effect of tape on FL change for the SL and LSL exercise. Compared to no-tape, the deload-tape resulted in less fascicle shortening during ankle plantar flexion, and more fascicle lengthening during ankle dorsiflexion. For the LSL exercise, deload-tape caused MG fascicles to operate at longer lengths, for a given joint angle. Diamond taping, with or without added tension, has only a small effect on ankle and MG fascicle kinematics during the heel raise-lower exercise. With the exception of the LSL exercise, both tape conditions resulted in similar changes in the FL-angle relations.

Impaired muscle growth precedes development of increased stiffness of the triceps surae musculotendinous unit in children with cerebral palsy.

AIM: If increased muscle stiffness and contractures in children with cerebral palsy (CP) are related to impaired muscle growth, reduced muscle growth should precede or coincide with increased muscle stiffness during development. Here, we compared the volume of the medial gastrocnemius muscle and the passive (non-neural) stiffness of the triceps surae musculotendinous unit in typically developing children and children with CP from birth until 4 years of age. METHOD: Forty-one children with CP and 45 typically developing children were included. Freehand three-dimensional ultrasound was used to evaluate the volume of the medial gastrocnemius muscle. Biomechanical and electrophysiological measures were used to determine passive and reflex mediated stiffness of the triceps surae musculotendinous unit. RESULTS: Medial gastrocnemius muscle volume increased with the same rate in typically developing and children with CP until 12 months of age, when a significant smaller rate of growth was observed in children with CP. Passive stiffness of the triceps surae musculotendinous unit showed a linear increase with age in typically developing children. Children with CP older than 27 months showed a significant increase in passive stiffness. Reflex mediated stiffness was only pathologically increased in four children with CP. INTERPRETATION: The deviation of medial gastrocnemius muscle volume, earlier than musculotendinous unit stiffness, is consistent with the hypothesis. The data also point out that muscle atrophy and muscle stiffness already develops within the first 1 to 2 years. This emphasizes the necessity of early interventions to promote lower limb muscle growth in this population. WHAT THIS PAPER ADDS: Medial gastrocnemius muscle growth is reduced in children with cerebral palsy (CP) around 12 months after birth. Triceps surae musculotendinous unit stiffness is increased in children with CP around 27 months after birth. Reflex excitability is rarely increased in children with CP. Reduced muscle growth may be involved in the pathophysiology of contractures.

Functional Capacity in Adults With Cerebral Palsy: Lower Limb Muscle Strength Matters.

OBJECTIVE: To investigate the relation between lower limb muscle strength, passive muscle properties, and functional capacity outcomes in adults with cerebral palsy (CP). DESIGN: Cross-sectional study. SETTING: Tertiary institution biomechanics laboratory. PARTICIPANTS: Adults with spastic-type CP (N=33; mean age, 25y; range, 15-51y; mean body mass, 70.15±21.35kg) who were either Gross Motor Function Classification System (GMFCS) level I (n=20) or level II (n=13). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Six-minute walk test (6MWT) distance (m), lateral step-up (LSU) test performance (total repetitions), timed up-stairs (TUS) performance (s), maximum voluntary isometric strength of plantar flexors (PF) and dorsiflexors (DF) (Nm.kg-1), and passive ankle joint and muscle stiffness. RESULTS: Maximum isometric PF strength independently explained 61% of variance in 6MWT performance, 57% of variance in LSU test performance, and 50% of variance in TUS test performance. GMFCS level was significantly and independently related to all 3 functional capacity outcomes, and age was retained as a significant independent predictor of LSU and TUS test performance. Passive medial gastrocnemius muscle fascicle stiffness and ankle joint stiffness were not significantly related to functional capacity measures in any of the multiple regression models. CONCLUSIONS: Low isometric PF strength was the most important independent variable related to distance walked on the 6MWT, fewer repetitions on the LSU test, and slower TUS test performance. These findings suggest lower isometric muscle strength contributes to the decline in functional capacity in adults with CP.

Shrink rethink: rebranding psychiatry.

Negative public attitudes towards psychiatry hinder individuals coming for treatment and prevent us from attracting and retaining the very brightest and best doctors. As psychiatrists we are skilled in using science to change the thoughts and behaviours of individuals, however, we lack the skills to engage entire populations. Expertise in this field is the preserve of branding, advertising and marketing professionals. Techniques from these fields can be used to rebrand psychiatry at a variety of levels from national recruitment drives to individual clinical interactions between psychiatrists and their patients.

Medial gastrocnemius and soleus muscle-tendon unit, fascicle, and tendon interaction during walking in children with cerebral palsy.

AIM: This study investigates the in vivo function of the medial gastrocnemius and soleus muscle-tendon units (MTU), fascicles, and tendons during walking in children with cerebral palsy (CP) and an equinus gait pattern. METHOD: Fourteen children with CP (9 males, 5 females; mean age 10y 6mo, standard deviation [SD] 2y 11mo; GMFCS level I=8, II=6), and 10 typically developing (6 males, 4 females; mean age 10y, SD 2y 1mo) undertook full body 3D gait analysis and simultaneous B-mode ultrasound images of the medial gastrocnemius and soleus fascicles during level walking. Fascicle lengths were analysed using a semi-automated tracking algorithm and MTUs using OpenSim. Statistical parametric mapping (two-sample t-test) was used to compare differences between groups (p<0.05). RESULTS: In the CP group medial gastrocnemius fascicles lengthened during mid-stance gait and remained longer into late-stance compared to the typically developing group (p<0.001). CP medial gastrocnemius fascicles shortened less during stance (1.16mm [SD 1.47mm]) compared to the typically developing group (4.48mm [SD 1.94mm], p<0.001). In the CP group the medial gastrocnemius and soleus MTU and tendon were longer during early- and mid-stance (p<0.001). Ankle power during push-off (p=0.015) and positive work (p<0.002) and net work (p<0.001) were significantly lower in the CP group. INTERPRETATION: Eccentric action of the CP medial gastrocnemius muscle fascicles during mid-stance walking is consistent with reduced volume and neuromuscular control of impaired muscle. Reduced ankle push-off power and positive work in the children with CP may be attributed to reduced active medial gastrocnemius fascicle shortening. These findings suggest a reliance on passive force generation for forward propulsion during equinus gait.

Randomized controlled trial of web-based multimodal therapy for children with acquired brain injury to improve gross motor capacity and performance.

OBJECTIVE: To compare efficacy of a web-based multimodal training programme, 'Move it to improve it' (MitiiTM), to usual care on gross motor capacity and performance for children with an acquired brain injury. DESIGN: Randomized waitlist controlled trial. SETTING: Home environment. PARTICIPANTS: A total of 60 independently ambulant children (30 in each group), minimum 12 months post-acquired brain injury were recruited and randomly allocated to receive either 20 weeks of MitiiTM training (30 minutes/day, six days/week, total 60 hours) immediately, or waitlisted (usual care control group) for 20 weeks. A total of 58 children completed baseline assessments (32 males; age 11 years 11 months ± 2 years 6 months; Gross Motor Function Classification System equivalent I = 29, II = 29). INTERVENTION: The MitiiTM program comprised of gross motor, upper limb and visual perception/cognitive activities. MAIN MEASURES: The primary outcome was 30-second, repetition maximum functional strength tests for the lower limb (sit-to-stand, step-ups, half-kneel to stand). Secondary outcomes were the 6-minute walk test, High-level Mobility Assessment Tool, Timed Up and Go Test and habitual physical activity as captured by four-day accelerometry. RESULTS: Groups were equivalent at baseline on demographic and clinical measures. The MitiiTM group demonstrated significantly greater improvements on combined score of functional strength tests (mean difference 10.19 repetitions; 95% confidence interval, 3.26-17.11; p = 0.006) compared with the control group. There were no other between-group differences on secondary outcomes. CONCLUSION: Although the MitiiTM programme demonstrated statistically significant improvements in the functional strength tests of the lower limb, results did not exceed the minimum detectable change and cannot be considered clinically relevant for children with an acquired brain injury. CLINICAL TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registration Number, ANZCTR12613000403730.

Characteristics associated with physical activity capacity and performance in children and adolescents with an acquired brain injury.

AIM: To examine characteristics associated with physical activity capacity and performance in children with acquired brain injury (ABI). METHODS: 58 children (32 men; age 11 years 11 months ± 2 years 6 months; Gross motor function classification system [GMFCS] equivalent I = 29, II = 29) >12 months post ABI were recruited. Physical activity capacity measures included: (i) combined score of three 30-second repetition maximum functional strength exercises; (ii) timed up and go; (iii) 6-minute walk test and (iv) high-level mobility assessment tool (HiMAT). Physical activity performance determined time spent in sedentary, light and moderate to vigorous physical activity (MVPA). Full scale intelligence quotient (FSIQ) was assessed using the Wechsler intelligence scale for Children-IV. Regression models were constructed with functional strength score (n = 56), activity counts/minutes and time spent in MVPA and sedentary (n = 37). RESULTS: The HiMAT and FSIQ explained 69% of the variance in functional strength. Age explained 12% of the variance in counts/min and 14% of the variance in time spent sedentary. GMFCS explained 10% of the variance in time spent in MVPA. CONCLUSIONS: The ability to perform functional strength exercises is associated with mobility beyond independence and adequate intellectual ability for children with ABI. Age was the most significant factor associated with physical activity performance, and interventions should target adolescents with ABI.

Reliability of Achilles Tendon Moment Arm Measured In Vivo Using Freehand Three-Dimensional Ultrasound.

This study investigated reliability of freehand three-dimensional ultrasound (3DUS) measurement of in vivo human Achilles tendon (AT) moment arm. Sixteen healthy adults were scanned on 2 separate occasions by a single investigator. 3DUS scans were performed over the free AT, medial malleolus, and lateral malleolus with the ankle passively positioned in maximal dorsiflexion, mid dorsiflexion, neutral, mid plantar flexion and maximal plantar flexion. 3D reconstructions of the AT, medial malleolus, and lateral malleolus were created from manual segmentation of the ultrasound images and used to geometrically determine the AT moment arm using both a straight (straight ATMA) and curved (curved ATMA) tendon line-of-action. Both methods were reliable within- and between-session (intra-class correlation coefficients > 0.92; coefficient of variation < 2.5 %) and revealed that AT moment arm increased by ∼ 7 mm from maximal dorsiflexion (∼ 41mm) to maximal plantar flexion (∼ 48 mm). Failing to account for tendon curvature led to a small overestimation (< 2 mm) of AT moment arm that was most pronounced in ankle plantar flexion, but was less than the minimal detectable change of the method and could be disregarded.

Validity of Accelerometry to Measure Physical Activity Intensity in Children With an Acquired Brain Injury.

PURPOSE: To evaluate the validity of the ActiGraph accelerometer (AG) to differentiate between standardized, physical activity tasks using oxygen consumption ((Equation is included in full-text article.)O2) as the criterion measure in children and adolescents with an acquired brain injury; to determine vector magnitude activity intensity cut-points; to compare performance of cut-points to previously published cut-points. METHODS: Twenty-seven children performed standardized walking and stepping activities wearing a portable indirect calorimeter, AG, and heart rate monitor. Differences in (Equation is included in full-text article.)O2 and AG vector magnitude activity counts were measured during activities. Receiver operating characteristic curves were determined for intensity cut-points. RESULTS: (Equation is included in full-text article.)O2 and AG activity counts significantly increased as walking speed increased. Discrimination of the newly derived cut-points was excellent and demonstrated greater agreement compared with the previously published cut-points. CONCLUSION: Output from accelerometers can differentiate physical activity intensity in children with an acquired brain injury. Future studies can apply these cut-points to evaluate physical activity performance.

Medial gastrocnemius muscle volume in ambulant children with unilateral and bilateral cerebral palsy aged 2 to 9 years.

AIM: Calf muscle growth in children with unilateral cerebral palsy (UCP) and bilateral cerebral palsy (BCP) is unknown. This cross-sectional study examines the medial gastrocnemius growth rates of ambulatory children with UCP and BCP compared with children with typical development (CTD), aged 2 to 9 years. METHOD: Fifty children with UCP (mean age 66mo [SD 18], 29 males, Gross Motor Function Classification System [GMFCS] I=32, II=18), 50 children with BCP (age 64mo [SD 19], 31 males, GMFCS I=21, II=29), and 78 CTD (age 64mo [SD 16], 40 males) participated in the study. The medial gastrocnemius muscle volume was measured at rest using a validated freehand three-dimensional (3D) ultrasound method. RESULTS: Normalized medial gastrocnemius muscle growth rate was significantly less in the children with UCP (0.001 mL/kg/mo) compared with the BCP (0.015 mL/kg/mo, p=0.001) and CTD (0.014 mL/kg/mo, p<0.001) groups. Normalized medial gastrocnemius muscle growth rate was the same in the BCP and CTD groups (p=0.77). INTERPRETATION: The normalized growth rate of the medial gastrocnemius muscle in children aged 2 to 9 years with UCP is significantly lower compared with children with BCP and CTD. The growth rate differences in the children with UCP compared with BCP raises questions about the underlying mechanisms that lead to reduced growth in each cerebral palsy (CP) group and potential differences in muscle recovery response in UCP and BCP following treatment.

Reproducibility in measuring physical activity in children and adolescents with an acquired brain injury.

AIM: To examine the reproducibility in measurement of physical activity performance using the ActiGraph® GT3X+ accelerometer in children aged 8-16 years with Acquired Brain Injury (ABI). METHODS: Reproducibility of standardized tasks: Thirty-two children with ABI (12 years 1 month, SD = 2 years 4 months; 20 males; Gross Motor Function Classification System I = 17, II = 15) performed the following activities on 2 consecutive days while wearing an accelerometer and a heart rate monitor: quiet sitting, slow walking (SW), moderate walking (MW), fast walking (FW) and rapid stepping on/off a block (STEP). Intra-class correlation coefficients (ICC) were calculated. Performance variability: Fifty-one participants (12 years 1 month, SD = 2 years 5 months; 27 males; GMFCS I = 26, II = 25) wore an accelerometer for 4 days in the community and reliability coefficients were calculated using standardized 12-hour time spent in moderate-to-vigorous physical activity (MVPA). RESULTS: Test-re-test reproducibility was excellent for all activities (SW, ICC = 0.90; MW, ICC = 0.83; FW, ICC = 0.91; STEP, ICC = 0.89). Three days of monitoring produced excellent variability estimates of MVPA (R = 0.78). CONCLUSION: Therapists can confidently use accelerometry as a reproducible measure of physical activity under standardized walking and stepping conditions, as well as in the community for children with ABI.

Systematic review of physiotherapy interventions to improve gross motor capacity and performance in children and adolescents with an acquired brain injury.

AIM: To systematically review the efficacy of physiotherapy interventions to improve gross motor capacity, performance and societal participation in children aged 5-17 years with an acquired brain injury (ABI). METHODS: Randomized and non-randomized controlled trials, cohort, case series, case-control and case studies were included and classified according to grades of evidence. Methodological quality of studies was assessed using the Downs and Black (D&B) scale and quantitative data was analysed using effect sizes. RESULTS: Two home-based studies investigated functional strength training (one randomized controlled trial, n = 20, level 2b, D&B = 16/32 and one non-randomized self-control study, n = 19, level 4, D&B = 15/32). Four studies evaluated virtual reality including: one pilot study, n = 50, level 4, D&B = 22/32; one single-subject, non-concurrent, randomized multiple baseline study, n = 3, level 4, D&B = 15/32; one case series study, n = 2, level 4, D&B = 15/32; one case study, n = 1, level 4, D&B = 15/32. Effect sizes for the randomized controlled trial ranged between 0.30-1.29 for the Functional Reach and Timed Up and Go outcome measures. CONCLUSION: There is preliminary evidence to support the efficacy of physiotherapy interventions to improve gross motor outcomes in children with an ABI. Both functional strength training and virtual-reality based therapy are potential treatment options for clinicians to prescribe in either home or clinical settings.

Test-re-test reproducibility of activity capacity measures for children with an acquired brain injury.

OBJECTIVE: To determine test-re-test reproducibility of the Timed Up & Go (TUG) test, 30-second repetition maximum (repmax) of functional exercises, 6-Minute Walk Test (6MWT) and High-level Mobility Assessment Tool (HiMAT) in children with Acquired Brain Injury (ABI). Secondarily, to assess the accuracy between hand-timed and video-timed scores for the TUG test and HiMAT. METHODS: Thirty children at least 1 year post-ABI (mean age at assessment = 11 years 11 months, SD = 2 years 4 months; 14 males; Gross Motor Function Classification Scale I = 17, II = 13) were assessed twice. Intra-class correlation coefficients (ICC), standard error of measurement and minimum detectable change (MDC) were determined. The Bland-Altman method and 95% limits of agreement (LOA) were used to assess the agreement between hand and video-timed TUG test and HiMAT scores. RESULTS: Test-re-test reproducibility was acceptable for the TUG test (ICC = 0.92; MDC = 1.2s); repmax of functional exercises (ICC = 0.84-0.98; MDC = 4-8 reps); 6MWT (ICC = 0.90; MDC = 69.38 m) and HiMAT (ICC = 0.98; MDC = 6). Comparison of hand and video scores for the TUG test and HiMAT demonstrated a mean difference of 0.23 (LOA = -0.3-0.7) and -0.07 (LOA = -1.99-1.85), respectively. Conclusions Test-re-test reproducibility of lower limb activity capacity measures in children with ABI are acceptable. The MDC scores provide a useful reference to interpret treatment effectiveness. Video timing was more accurate than hand-timing for the TUG test.

Mitii™ ABI: study protocol of a randomised controlled trial of a web-based multi-modal training program for children and adolescents with an Acquired Brain Injury (ABI).

BACKGROUND: Acquired brain injury (ABI) refers to multiple disabilities arising from damage to the brain acquired after birth. Children with an ABI may experience physical, cognitive, social and emotional-behavioural impairments which can impact their ability to participate in activities of daily living (ADL). Recent developments in technology have led to the emergence of internet-delivered therapy programs. "Move it to improve it" (Mitii™) is a web-based multi-modal therapy that comprises upper limb (UL) and cognitive training within the context of meaningful physical activity. The proposed study aims to compare the efficacy of Mitii™ to usual care to improve ADL motor and processing skills, gross motor capacity, UL and executive functioning in a randomised waitlist controlled trial. METHODS/DESIGN: Sixty independently ambulant children (30 in each group) at least 12 months post ABI will be recruited to participate in this trial. Children will be matched in pairs at baseline and randomly allocated to receive either 20 weeks of Mitii™ training (30 min per day, six days a week, with a potential total dose of 60 h) immediately, or be waitlisted for 20 weeks. Outcomes will be assessed at baseline, immediately post-intervention and at 20 weeks post-intervention. The primary outcomes will be the Assessment of Motor and Process Skills and 30 s repetition maximum of functional strength exercises (sit-to-stand, step-ups and half kneel to stand). Measures of body structure and functions, activity, participation and quality of life will assess the efficacy of Mitii™ across all domains of the International Classification of Functioning, Disability and Health framework. A subset of children will undertake three tesla (3T) magnetic resonance imaging scans to evaluate functional neurovascular changes, structural imaging, diffusion imaging and resting state functional connectivity before and after intervention. DISCUSSION: Mitii™ provides an alternative approach to deliver intensive therapy for children with an ABI in the convenience of the home environment. If Mitii™ is found to be effective, it may offer an accessible and inexpensive intervention option to increase therapy dose. TRIAL REGISTRATION: ANZCTR12613000403730.

Mild untreated hypercholesterolaemia affects mechanical properties of the Achilles tendon but not gastrocnemius muscle.

Tendon xanthoma and altered mechanical properties have been demonstrated in people with familial hypercholesterolaemia. However, it is unclear whether mild, untreated hypercholesterolaemia alters musculotendinous mechanical properties and muscle architecture. We conducted a case-control study of adults aged 50 years and over, without lower limb injury or history of statin medication. Based on fasting low-density lipoprotein (LDL) cholesterol levels, 6 participants had borderline high LDL (>3.33 mmol/L) and 6 had optimal LDL cholesterol (<2.56 mmol/L). Using shear wave elastography, shear wave velocity (SWV) of the Achilles tendon and gastrocnemius medialis muscle (a proxy for stiffness), along with muscle fascicle length and pennation angle were measured under four passive tensile loads (0, 0.5, 1.0, 1.5 kg) applied via a pulley system. Differences between groups were found for tendon SWV but not muscle SWV, fascicle length or pennation angle. Participants with hypercholesterolaemia showed greater SWV (mean difference, 95 % CI: 2.4 m/s, 0.9 to 4.0, P = 0.024) compared to the control group across all loads. These findings suggest that adults with mild hypercholesterolaemia have increased tendon stiffness under low passive loads, while muscle was not affected. Future research is needed to confirm findings in a larger cohort and explore the impact of hypercholesterolaemia on tendon fatigue injury and tendinopathy.

The size and echogenicity of the tibialis anterior muscle is preserved in both limbs in young children with unilateral spastic cerebral palsy.

PURPOSE: The primary of this study was to compare the volume, length, echo intensity, and growth rate of the medial gastrocnemius (MG) and tibialis anterior (TA) muscle of both limbs (more-involved and less-involved) in children with unilateral spastic cerebral palsy (USCP), with those of an age-matched typically developing (TD) group. A secondary aim in the USCP group was to explore the associations between these muscle parameters and discrete ankle positions during phase of gait. METHODS: Muscle parameters were assessed using 3D ultrasound. Maximal ankle dorsiflexion in stance and swing during walking were determined from 2D video analysis. Group differences in muscle size and echo intensity were assessed using a two-way analysis of covariance (age-by-group), with the interaction term used to compare muscle growth rates. Associations between muscle parameters and maximal ankle dorsiflexion in stance and swing were assessed using backwards multiple linear regression analyses. RESULTS: The MG of both limbs in children with USCP had signs of impaired muscle development (smaller volume and length, higher echo intensity and lower growth rate). There was no evidence of impaired muscle development of TA between limbs or compared the TD children. Tibialis anterior volume, length, echo intensity and MG volume explained 66% and 83% of the variance in maximal ankle dorsiflexion position in the stance and swing phases of walking, respectively. CONCLUSIONS: Unlike the MG, the TA volume and growth rate in children with USCP are equivalent between limbs and compared to TD children. For the more-involved limb only, TA volume, length, and echo intensity appear associated with maximal ankle dorsiflexion during walking and represent important muscle parameters that could be targeted in with early exercise therapy.Implications for rehabilitationTibialis anterior (TA) size and echogenicity appear normal in both limbs in young children with unilateral spastic cerebral palsy (USCP); findings that could indicate sufficient mechanical stimulus and muscle anabolism to maintain normal muscle growth.Tibialis anterior size and echogenicity are associated with maximal ankle dorsiflexion in both stance and swing phase of walking in young children with USCP; though such relations appear isolated to the more-involved limb.Early therapeutic interventions that target TA are likely to be successful in maintaining muscle size and may offset the negative effects of medial gastrocnemius atrophy in the development of fixed ankle equinus of the more-involved limb and improve ankle positioning during gait.