Melissa K. Licari

Adding sprints to continuous exercise at the intensity that maximises fat oxidation: Implications for acute energy balance and enjoyment

The objective was to examine the effect of adding sprints to continuous exercise at the intensity that maximises fat oxidation (Fat(max)) on energy expenditure, substrate oxidation, enjoyment and post-exercise energy intake in boys. Nine overweight and nine normal weight boys (8-12 years) attended the laboratory on three mornings. First, body anthropometrics, peak aerobic capacity and Fat(max) were assessed. On the remaining two sessions, resting metabolic rate was determined before participants completed 30 min of either continuous cycling at Fat(max) (MOD) or sprint interval exercise consisting of continuous cycling at Fat(max) interspersed with four-second maximal sprints every two minutes (SI). Energy expenditure and substrate oxidation were measured during exercise and for 30 min post-exercise, while participants completed a modified Physical Activity Enjoyment Scale (PACES). This was followed by a buffet-like breakfast to measure post-exercise energy intake. Fat oxidation rate was similar between groups and protocols (P>0.05). Both groups expended more energy with SI compared to MOD, resulting from increased carbohydrate oxidation (P<0.05), which was not compensated by increased energy intake. Participants indicated that they preferred SI more than MOD, although there was no significant difference in PACES score between the protocols (P>0.05). In summary, the addition of short sprints to continuous exercise at Fat(max) increased energy expenditure without compromising fat oxidation or stimulating increased post-exercise energy intake. The boys preferred SI and did not perceive it to be any harder than MOD, indicating that sprint interval exercise should be considered in exercise prescription for this population.

Assessment of Motor Functioning in the Preschool Period

The assessment of motor functioning in young children has become increasingly important in recent years with the acknowledgement that motor impairment is linked with cognitive, language, social and emotional difficulties. However, there is no one gold standard assessment tool to investigate motor ability in children. The aim of the current paper was to discuss the issues related to the assessment of motor ability in young pre-school children and to provide guidelines on the best approach for motor assessment. The paper discusses the maturational changes in brain development at the preschool level in relation to motor ability. Other issues include sex differences in motor ability at this young age, and evidence for this in relation to sociological versus biological influences. From the previous literature it is unclear what needs to be assessed in relation to motor functioning. Should the focus be underlying motor processes or movement skill assessment? Several key assessment tools are discussed that produce a general measure of motor performance followed by a description of tools that assess specific skills, such as fine and gross motor, ball and graphomotor skills. The paper concludes with recommendations on the best approach in assessing motor function in pre-school children.

A comparison of the oxygen cost of locomotion in children with and without developmental coordination disorder

Aim  The aim of this study was to compare the oxygen cost (V̄o2) of walking and running, as well as aerobic fitness, in children with and without developmental coordination disorder (DCD).

Increased associated movements: Influence of attention deficits and movement difficulties

This study was designed to examine whether increased associated movements (AMs) reflect motor difficulties or the symptoms associated with attention disorders. Four groups of male children (N=51) aged 6-8 years participated: Group 1 consisted of 13 children diagnosed with developmental coordination disorder (DCD); Group 2 consisted of 13 children diagnosed with attention deficit hyperactivity disorder (ADHD); Group 3 consisted of 10 children diagnosed with co-occurring DCD and ADHD, and Group 4 was a control sample of 15 children, with no known movement or attention difficulties. Various AM tasks were selected from established assessments and previous research to measure AM severity. The results supported the hypothesis that increased severity of AMs reflect movement difficulties with children in the DCD and DCD/ADHD groups displaying significantly more AMs than children in the ADHD and control groups (p<.001). No differences were found between the ADHD only and control groups (p=.67) or the DCD and DCD/ADHD groups (p=.81) suggesting that AM severity is not influenced by the neurodevelopmental symptoms associated with ADHD.

Cognitive Orientation to (Daily) Occupational Performance intervention leads to improvements in impairments, activity and participation in children with Developmental Coordination Disorder

Abstract Introduction: Children diagnosed with Developmental Coordination Disorder (DCD) present with a variety of impairments in fine and gross motor function, which impact on their activity and participation in a variety of settings. This research aimed to determine if a 10-week group-based Cognitive Orientation to Daily Occupational Performance (CO-OP) intervention improved outcome measures across the impairment, activity and participation levels of the International Classification of Functioning, Disability and Health (ICF) framework. Methods: In this quasi-experimental, pre–post-test, 20 male children aged 8–10 years (9y1m ± 9 m) with a confirmed diagnosis of DCD participated in either the 10 week group intervention based on the CO-OP framework (n = 10) or in a control period of regular activity for 10 weeks (n = 10). Outcome measures relating to impairment (MABC-2, motor overflow assessment), activity (Handwriting Speed Test) and participation [Canadian Occupational Performance Measure, (COPM) and Goal Attainment Scale) were measured at weeks 0 and 10 in the intervention group. Results: Children who participated in the CO-OP intervention displayed improvements in outcome measures for impairment, activity and participation, particularly a reduction in severity of motor overflow. Parent and child performance and satisfaction ratings on the COPM improved from baseline to week 10 and all goals were achieved at or above the expected outcome. No significant changes were reported for the control group in impairment and activity (participation was not measured for this group). Conclusion: The strategies implemented by children in the CO-OP treatment group, targeted towards individualised goal attainment, show that CO-OP, when run in a group environment, can lead to improvements across all levels of the ICF. Implications for Rehabilitation Development Coordination Disorder is a condition which has significant physical, academic and social impacts on a child and can lead to activity limitations and participation restrictions. Cognitive Orientation to Daily Occupational Performance is an approach which uses cognitive-based strategies to improve performance of specific tasks based on child chosen goals. The intervention program had a positive effect on self-perceived levels of performance which may lead to changes in quality of life. Parents felt the intervention enhanced socialisation, peer modelling and encouragement and felt that this increased confidence and independence.

Attention deficit hyperactivity disorder and developmental coordination disorder: Two separate disorders or do they share a common etiology.

Attention deficit hyperactivity disorder (ADHD) has been described as the most prevalent behavioral disorder in children. Developmental coordination disorder (DCD) is one of the most prevalent childhood movement disorders. The overlap between the two conditions is estimated to be around 50%, with both substantially interfering with functioning and development, and leading to poorer psychosocial outcomes. This review provides an overview of the relationship between ADHD and DCD, discussing the common presenting features, etiology, neural basis, as well as associated deficits in motor functioning, attention and executive functioning. It is currently unclear which specific motor and cognitive difficulties are intrinsic to each disorder as many studies of ADHD have not been screened for DCD and vice-versa. The evidence supporting common brain underpinnings is still very limited, but studies using well defined samples have pointed to non-shared underpinnings for ADHD and DCD. The current paper suggests that ADHD and DCD are separate disorders that may require different treatment approaches.

Childhood muscle morphology and strength: Alterations over six months of growth.

The purpose of this study was to establish the nature and stability of the strength‐size relationship for the knee flexors and extensors across a 6‐month period of childhood growth.

Does muscle size matter? The relationship between muscle size and strength in children with cerebral palsy

Abstract Purpose: To investigate the muscle size–strength relationship of the knee flexors and extensors in children with spastic cerebral palsy (CP) in relation to typically developing children (TD). Methods: Eighteen children with spastic Diplegia, Gross Motor Function Classification System I–III (mean 7 y 5 mo SD 1 y 7 mo) and 19 TD children (mean 7 y 6 mo SD 1 y 9 mo) participated. Muscle volume (MV) and anatomical cross-sectional area (aCSA) were assessed using MRI. Measures of peak torque (PT) and work of the knee flexors and extensors were assessed isometrically and isokinetically using a Biodex dynamometer, and normalised to bodymass (Bm). Results: Children with CP were weaker than their TD peers across all torque variables (p < 0.05). MV and aCSA of the knee flexors (MV: p = 0.002; aCSA: p = 0.000) and extensors (MV: p = 0.003; aCSA: p < 0.0001) were smaller in children with CP. The relationship between muscle size and strength in children with CP was weaker than the TD children. The strongest relationship was between MV and isometric PT/Bm for TD children (r = 0.77–0.84), and between MV and isokinetic work (r = 0.70–0.72) for children with CP. Conclusions: Children with CP have smaller, weaker muscles than their TD peers. However, muscle size may only partially explain their decreased torque capacity. MV appears to be a better predictor of muscle work in children with CP than aCSA. This is an important area of research particularly in regard to treatment(s) that target muscle and strength in children with CP. Implications for Rehabilitation This research adds to the evidence that children with CP have smaller, weaker knee flexor and extensor muscles than their TD peers. However, unlike their TD peers, muscle size does not necessarily relate to muscle strength. The weak correlation between MRI-derived muscle volume and isometric peak torque suggests children with CP are underpowered relative to their muscle size. For children with CP, muscle volume appears to be the best predictor of isokinetic muscle torque output. Therefore, when assessing the capacity of a muscle, it appears preferable to measure total muscle volume and torque development through a range of motion (isokinetic strength).

A comparison of running kinematics and kinetics in children with and without developmental coordination disorder

The aim of this study was to compare running gait in children with and without developmental coordination disorder (DCD). Fourteen boys with DCD (9.5 ± 1 yr) and 14 typically developing (TD) controls (9.6 ± 1 yr) ran at a velocity of 2.44 ± 0.25 m/s along a 15m track, with kinematic and kinetic data of the trunk and lower limb obtained for three cycles of each limb using a 12-camera Vicon MX system and AMTI force plate. Although features of the kinematic and kinetic trajectories were similar between groups, the DCD group displayed decreased peak knee extension compared with the TD group prior to initial foot contact (p = 0.016). Furthermore, the DCD group displayed increased variability in sagittal plane kinematics at the hip and ankle during toe off compared with the TD group. Kinetic analysis revealed that children with DCD displayed significantly reduced knee extensor moments during the stance phase of the running cycle (p = 0.033). Consequently, peak knee power absorption and ankle power generation was significantly lower in the DCD group (p = 0.041; p = 0.017). Furthermore, there was a trend for children with DCD to have shorter strides (p = 0.052, ES = 0.499) and a longer stance period than the TD controls (p=0.06, ES = 0.729). These differences may have implications for the economy of running and subsequently the planning of targeted intervention programs to improve running gait in children with DCD.

A review of five tests to identify motor coordination difficulties in young adults.

Difficulties with low motor competence in childhood and adolescence, such as that seen in Developmental Coordination Disorder (DCD), often persist into adulthood. Identification of DCD at all ages is particularly challenging and problematic because of the diversity of motor symptoms. Many tests of motor proficiency and impairment have been developed for children up to 12 years of age. Whilst identification of DCD is important during childhood, it is of equal importance to identify and monitor the impact of this impairment as an individual grows and develops. Currently there is no test specifically designed to support diagnosis and monitor change in the age range 16-30 years. In this article we review five tests that have been used to assess motor competence among young adults (Bruininks-Oseretsky Test of Motor Proficiency-2, McCarron Assessment of Neuromuscular Development, Movement Assessment Battery for Children-2, Tufts Assessment of Motor Performance and the Zurich Neuromotor Assessment). Key issues relevant to testing motor skills in older populations, such as the inclusion of age appropriate skills, are explored. While the BOT-2 provided the most evidence for valid and reliable measurement of Criterion A of the diagnostic criteria for DCD among this age group, no test adequately evaluated Criterion B. Further evaluation of motor skill assessment among the young adult population is needed.