Prioritizing family-centered developmental care: insights from parents of children with critical congenital heart disease: a qualitative study.

As survivors of early cardiac surgery are at high risk of neurodevelopmental impairments, systematic health observations of children with critical congenital heart disease (CCHD) throughout childhood are recommended to enable early diagnosis and offer interventions to optimize neurodevelopment. A qualitative study using thematic analysis was performed to explore parents' concerns, experiences, and needs regarding the development and received developmental care of their child (0-10 years) during hospital admission and beyond. Data were collected using semi-structured online interviews with 20 parents of children with CCHD. Four major themes were identified: (1) "impact of diagnosis and disease on the family-system," (2) "parental concerns from diagnoses and beyond," (3) "the need for information," and (4) "the need for individualized and family-centered care." The main themes can be divided into 13 sub-themes as impact, concerns, and needs are influenced by various impactful moments from diagnosis and afterwards.     Conclusion: This study confirms the importance of early identification of neurodevelopmental problems by experienced healthcare professionals, especially in the early years when parental expectations and concerns about their child's neurodevelopment are lower. A tailor-made family-centered follow-up program should be offered, which pays attention to both the neurodevelopment of patients with CCHD as well as the mental wellbeing of the entire family system. Furthermore, an online portal is recommended with a variety of reliable, controlled, understandable information from which parents can obtain the desired information to understand better the consequences of specific heart condition and to provide their child with the best possible guidance. What is Known: • Survivors of early cardiac surgery are at high risk of neurodevelopmental impairments; systematic health observations of children with CCHD throughout childhood are strongly recommended. What is New: • Parents need a tailor-made family-centered follow-up program, which pays attention to both the neurodevelopment of patients with CCHD as well as the mental wellbeing of the entire family system. • An online portal offering diverse, trustworthy information and sources would effectively meet parents' needs by providing accessible insights into the potential consequences of specific heart conditions and guiding them in supporting their child optimally.

Is Measuring Physical Literacy in School-Aged Children With Cystic Fibrosis or Congenital Heart Disease Needed?

PURPOSE: To explore the association between cardiorespiratory fitness and other physical literacy domains in children with cystic fibrosis (CF) or congenital heart disease (CHD). METHODS: In 28 children with CF (n = 10) or CHD (n = 18), aged 7 to 11 years, cardiorespiratory fitness and the following physical literacy domains were measured: ( a ) physical competence, ( b ) motivation and confidence, ( c ) knowledge and understanding, and ( d ) daily behavior (ie, self-perceived moderate-to-vigorous physical activity [MVPA]). RESULTS: Cardiorespiratory fitness was significantly associated with motivation and confidence and self-perceived MVPA. There were no other significant associations. CONCLUSIONS: Cardiorespiratory fitness is associated with self-perceived MVPA, motivation, and confidence in children with CF or CHD.

Severe Fatigue Is Common Among Pediatric Patients with Primary Immunodeficiency and Is Not Related to Disease Activity.

PURPOSE: Fatigue is a distressing symptom commonly reported among pediatric patients with primary immunodeficiency (PID). However, the relationship between fatigue and disease activity is currently unknown. METHODS: In this cross-sectional study, we examined the prevalence of severe fatigue, the effect of fatigue on health-related quality of life (HRQoL), and the effects of disease activity and comorbidity on fatigue severity among pediatric patients 2-18 years of age with PID. Fatigue and HRQoL were assessed using the pediatric quality of life inventory multidimensional fatigue scale (PedsQL MFS) and generic core scales (PedsQL GCS), respectively. Linear regression analyses and an analysis of covariance were used to compare the fatigue scores with the scores obtained from a healthy control group. Data were adjusted for age and sex. RESULTS: Of the 91 eligible patients, 79 were assessed (87% participation rate), with a mean age of 10.4 ± 4.4 years. Pediatric patients with PID reported significantly higher fatigue levels compared to healthy peers, with an 18.9% prevalence of severe fatigue. Moreover, higher fatigue levels were inversely associated with HRQoL in all domains and directly associated with school absences. We found that severe fatigue was comparable between common variable immunodeficiency (CVID), combined immunodeficiency (CID), and selective immunoglobulin A deficiency (SIgAD) patients, but was not reported in the X-linked agammaglobulinemia (XLA) patients studied. Finally, fatigue severity was not significantly associated with disease activity or comorbidity. CONCLUSIONS: Nearly 20% of pediatric patients with PID reported experiencing severe fatigue, and fatigue was reported among a wide range of PID subcategories. In addition, severe fatigue negatively affected the patient's quality of life and daily functioning, but was not associated with disease activity or comorbidity. Thus, targeting severe fatigue might be a promising strategy for improving the overall well-being and quality of life of pediatric patients with PID.

Motor Developmental Delay After Cardiac Surgery in Children With a Critical Congenital Heart Defect: A Systematic Literature Review and Meta-analysis.

PURPOSE: To systematically review evidence regarding the severity and prevalence of motor development in children with a critical congenital heart defect (CCHD) without underlying genetic anomalies. SUMMARY OF KEY POINTS: Twelve percent of all included studies reported abnormal mean motor developmental scores, and 38% reported below average motor scores. Children with single-ventricle physiology, especially those with hypoplastic left heart syndrome, had the highest severity and prevalence of motor delay, particularly at 0 to 12 months. Most included studies did not differentiate between gross and fine motor development, yet gross motor development was more affected. RECOMMENDATIONS FOR CLINICAL PRACTICE: We recommend clinicians differentiate between the type of heart defect, fine and gross motor development, and the presence of genetic anomalies. Furthermore, increased knowledge about severity and prevalence will enable clinicians to tailor their interventions to prevent motor development delays in CCHD.

A Systematic Approach to Interpreting the Cardiopulmonary Exercise Test in Pediatrics.

The use of cardiopulmonary exercise testing in pediatrics provides critical insights into potential physiological causes of unexplained exercise-related complaints or symptoms, as well as specific pathophysiological patterns based on physiological responses or abnormalities. Clinical interpretation of the results of a cardiopulmonary exercise test in pediatrics requires specific knowledge with regard to pathophysiological responses and interpretative strategies that can be adapted to address concerns specific to the child's medical condition or disability. In this review, the authors outline the 7-step interpretative approach that they apply in their outpatient clinic for diagnostic, prognostic, and evaluative purposes. This approach allows the pediatric clinician to interpret cardiopulmonary exercise testing results in a systematic order to support their physiological reasoning and clinical decision making.

Consensus-based recommendations for the management of juvenile dermatomyositis.

BACKGROUND: In 2012, a European initiative called Single Hub and Access point for pediatric Rheumatology in Europe (SHARE) was launched to optimise and disseminate diagnostic and management regimens in Europe for children and young adults with rheumatic diseases. Juvenile dermatomyositis (JDM) is a rare disease within the group of paediatric rheumatic diseases (PRDs) and can lead to significant morbidity. Evidence-based guidelines are sparse and management is mostly based on physicians' experience. Consequently, treatment regimens differ throughout Europe. OBJECTIVES: To provide recommendations for diagnosis and treatment of JDM. METHODS: Recommendations were developed by an evidence-informed consensus process using the European League Against Rheumatism standard operating procedures. A committee was constituted, consisting of 19 experienced paediatric rheumatologists and 2 experts in paediatric exercise physiology and physical therapy, mainly from Europe. Recommendations derived from a validated systematic literature review were evaluated by an online survey and subsequently discussed at two consensus meetings using nominal group technique. Recommendations were accepted if >80% agreement was reached. RESULTS: In total, 7 overarching principles, 33 recommendations on diagnosis and 19 recommendations on therapy were accepted with >80% agreement among experts. Topics covered include assessment of skin, muscle and major organ involvement and suggested treatment pathways. CONCLUSIONS: The SHARE initiative aims to identify best practices for treatment of patients suffering from PRD. Within this remit, recommendations for the diagnosis and treatment of JDM have been formulated by an evidence-informed consensus process to produce a standard of care for patients with JDM throughout Europe.

Trajectories of cardiorespiratory fitness in patients with juvenile dermatomyositis.

Objectives: Previous research demonstrated decreased cardiorespiratory fitness (CRF) in patients with JDM during active disease and remission. However, longitudinal data regarding trajectories of CRF are currently lacking. The objective of this study was to determine trajectories of CRF in patients with both monocyclic and chronic JDM, and to identify potential predictors of these trajectories. Methods: Thirty-six patients with JDM [median age (interquartile range) at diagnosis: 8.3 (6.3-15.4) years] treated in our paediatric rheumatology outpatient clinic were included. All patients performed multiple cardiopulmonary exercise tests between 2003 and 2016. Relevant CRF parameters were analysed, including peak oxygen uptake, maximal workload, mechanical efficacy and oxygen uptake at ventilatory anaerobic threshold. We analysed trajectories up to 10 years after diagnosis and determined predictors of CRF outcome parameters by multilevel analyses. Results: Trajectories demonstrated significant declines in CRF during the active phase of the disease with subsequent improvement in CRF during the initial years after diagnosis. However, hereafter no further improvements, and even a decrease, in CRF were observed over time in both monocyclic and chronic subtypes of JDM. We found that a longer disease duration, younger age of onset and higher prednisone dose negatively influence CRF. Conclusion: Patients with both monocyclic and chronic JDM show decreases in long-term CRF trajectories. Longer disease duration, younger age of onset and higher prednisone dose negatively influence CRF. This study stresses the need for regular evaluation of CRF and implementation of (exercise) interventions to improve CRF in patients with JDM, even in monocyclic patients.

Muscles in motion: a randomized controlled trial on the feasibility, safety and efficacy of an exercise training programme in children and adolescents with juvenile dermatomyositis.

OBJECTIVE: To study for the first time in a randomized controlled trial the feasibility, safety and efficacy of an exercise training programme in children and adolescents with JDM. METHODS: Patients were randomly assigned to the Intervention Group (IG; n = 14) or Waiting Control Group (WCG; n = 12). The intervention comprised an individually tailored 12-week home-based exercise programme of treadmill interval training and strength exercises. The efficacy of the IG over usual care (WCG) was examined with mixed linear regression (intention-to-treat). Effect sustainability during 12 weeks follow-up was also examined. RESULTS: Seventy-five percent of the participants completed the intervention. Reasons for discontinuation were motivation/fatigue, recurrent infections and increasing physical complaints. No hospitalizations occurred and immune suppressive therapy remained stable or decreased in the patients who participated in the intervention. The estimated marginal means after the intervention period were significantly in favour of the IG compared with the WCG for standing long jump distance [difference between groups (95% CI): 13 cm (2-23)], the 30-s number of push-ups [8 (3-13)] and sit-ups [4 (0.4-8)], and the parent Childhood Health Assessment Questionnaire 30 + 8 score [-0.13 (-0.24 to - 0.01)] and effects sustained at follow-up. A trend was seen for the maximal oxygen uptake divided by body mass during maximal exercise treadmill testing; the IG scored 3.0 ml/kg/min (-1.3 to 7.3) higher compared with the WCG. Other outcomes (e.g. isometric muscle strength and perception of fatigue) did not differ between IG and WCG. CONCLUSION: Exercise training is of value in the clinical management of JDM.

Quantitative muscle ultrasonography in the follow-up of juvenile dermatomyositis.

INTRODUCTION: We explored the use of quantitative muscle ultrasonography (QMUS) for follow-up of juvenile dermatomyositis (JDM). METHODS: Seven JDM patients were evaluated at diagnosis and 1, 3, 6, 12, and 24 months using the Childhood Myositis Assessment Scale (CMAS) and QMUS. Muscle thickness (MT) and quantitative muscle echo intensity (EI) were assessed with QMUS in 4 muscles. RESULTS: Six patients experienced a monocyclic course. At diagnosis EI was slightly increased, and MT was relatively normal. After start of treatment MT first decreased and EI increased, with normalization of EI within 6-12 months (n = 4). One patient had higher EIs at diagnosis and slower normalization, indicating fibrosis, despite early normalization of CMAS. One patient experienced a chronic course, with high EIs and atrophy during follow-up. CONCLUSIONS: QMUS can provide additional information for follow-up of JDM regarding disease severity and residual muscle damage, particularly after normalization of CMAS.

Near-infrared spectroscopy during exercise and recovery in children with juvenile dermatomyositis.

INTRODUCTION: We hypothesized that microvascular disturbances in muscle tissue play a role in the reduced exercise capacity in juvenile dermatomyositis (JDM). METHODS: Children with JDM, children with juvenile idiopathic arthritis (clinical controls), and healthy children performed a maximal incremental cycloergometric test from which normalized concentration changes in oxygenated hemoglobin (Δ[O2 Hb]) and total hemoglobin (Δ[tHb]) as well as the half-recovery times of both signals were determined from the vastus medialis and vastus lateralis muscles using near-infrared spectroscopy. RESULTS: Children with JDM had lower Δ[tHb] values in the vastus medialis at work rates of 25%, 50%, 75%, and 100% of maximal compared with healthy children; the increase in Δ[tHb] with increasing intensity seen in healthy children was absent in children with JDM. Other outcome measures did not differ by group. CONCLUSIONS: The results suggest that children with JDM may experience difficulties in increasing muscle blood volume with more strenuous exercise.

Physical activity in relation to motor performance, exercise capacity, sports participation, parental perceptions, and overprotection in school aged children with a critical congenital heart defect.

OBJECTIVE: To depict objectively measured moderate-to-vigorous physical activity (MVPA), motor performance (MP), cardiorespiratory fitness (CRF), organized sports participation, parental perceptions of vulnerability and parenting style in children with a Critical Congenital Heart Disease (CCHD), and to explore whether these factors are associated with MVPA. STUDY DESIGN: A prospective observational cohort study in 62 7-10 years old children with a CCHD. RESULTS: On average, children with CCHD spent 64 min on MVPA per day (accelerometry), 61 % met the international WHO physical activity guideline. Only 12 % had >60 min of MVPA daily. Eighteen percent had a motor delay (movement-assessment-battery-for children-II) and 38 % showed a below average CRF (cardiopulmonary exercise test using the Godfrey ramp protocol). Seventy-seven percent participated in organized sports activities at least once a week. Twenty-one percent of the parents are classified as overprotective (parent protection scale) and 7.3 % consider their child as being vulnerable (child vulnerability scale). A significant positive association was found between MVPA and MP (rs = 0.359), CRF(V̇O2peak/ml/kg: rs = 0.472 and Wpeak/kg: rs = 0.396) and sports participation (rs = 0.286). Children who were perceived as vulnerable by their parents showed a significantly lower MVPA (rs = -0.302). No significant associations were found between mean MVPA and parental overprotection. CONCLUSION: Even though the majority of school aged children with a CCHD is sufficiently active, counseling parents regarding the importance of sufficient MVPA and sports participation, especially in parents who consider their child being vulnerable, could be useful. Since motor delays can be detected at an early age, motor development could be an important target to improve exercise capacity and sports participation to prevent inactivity in children with a CCHD.

Design of a cross-sectional study on physical fitness and physical activity in children and adolescents after burn injury.

BACKGROUND: Burn injuries have a major impact on the patient's physical and psychological functioning. The consequences can, especially in pediatric burns, persist long after the injury. A decrease in physical fitness seems logical as people survive burn injuries after an often extensive period of decreased activity and an increased demand of proteins leading to catabolism, especially of muscle mass. However, knowledge on the possibly affected levels of physical fitness in children and adolescents after burn injury is limited and pertains only to children with major burns. The current multidimensional study aims to determine the level of physical fitness, the level of physical activity, health-related quality of life and perceived fatigue in children after a burn injury. Furthermore, interrelations between those levels will be explored, as well as associations with burn characteristics. METHODS/DESIGN: Children and adolescents in the age range of 6 up to and including 18 years are invited to participate in this cross-sectional descriptive study if they have been admitted to one of the three Dutch burn centers between 6 months and 5 years ago with a burn injury involving at least 10% of the total body surface area and/or were hospitalized ≥ 6 weeks. Physical fitness assessments will take place in a mobile exercise lab. Quantitative measures of cardiorespiratory endurance, muscular strength, body composition and flexibility will be obtained. Outcomes will be compared with Dutch reference values. Physical activity, health-related quality of life and fatigue will be assessed using accelerometry and age-specific questionnaires. DISCUSSION: The findings of the current study will contribute to a better understanding of the long-term consequences of burn injury in children and adolescents after burns. The results can guide rehabilitation to facilitate a timely and optimal physical recovery. TRIAL REGISTRATION: The study is registered in the National Academic Research and Collaborations Information System of the Netherlands (OND1348800).

Design of the muscles in motion study: a randomized controlled trial to evaluate the efficacy and feasibility of an individually tailored home-based exercise training program for children and adolescents with juvenile dermatomyositis.

BACKGROUND: Juvenile dermatomyositis (JDM) is a rare, often chronic, systemic autoimmune disease of childhood, characterized by inflammation of the microvasculature of the skeletal muscle and skin. Prominent clinical features include significant exercise intolerance, muscle weakness, and fatigue. Despite pharmacological improvements, these clinical features continue to affect patients with JDM, even when the disease is in remission. Exercise training is increasingly utilized as a non-pharmacological intervention in the clinical management of (adult) patients with chronic inflammatory conditions; however no randomized controlled trials (RCT) have been performed in JDM. In the current study, the efficacy and feasibility of an exercise training program in patients with JDM will be examined. METHODS/DESIGN: Subjects (n = 30) will include 8-18 year olds diagnosed with JDM. The intervention consists of an individually tailored 12-weeks home-based exercise training program in which interval training on a treadmill is alternated with strength training during each session. The program is based on previous literature and designed with a defined frequency, intensity, time, and type of exercise (FITT principles). Primary outcome measures include aerobic exercise capacity, isometric muscle strength, and perception of fatigue. The study methodology has been conceived according to the standards of the CONSORT guidelines. The current study will be a multi-center (4 Dutch University Medical Centers) RCT, with the control group also entering the training arm directly after completion of the initial protocol. Randomization is stratified according to age and gender. DISCUSSION: The current study will provide evidence on the efficacy and feasibility of an individually tailored 12-week home-based exercise training program in youth with JDM. TRIAL REGISTRATION: Medical Ethics Committee of the University Medical Center Utrecht, the Netherlands: 11-336; Netherlands Trial Register (NTR): NTR 3184.

Longitudinal Motor-Developmental Outcomes in Infants with a Critical Congenital Heart Defect.

Infants with critical congenital heart defects (CCHDs) are at increased risk for neurodevelopmental delays. The early identification of motor delays is clinically relevant to prevent or reduce long-term consequences. The current study aims to describe the motor-developmental pathways of infants with a CCHD. Motor development was assessed in 215 infants and toddlers using the Dutch version of the Bayley-III. At 3 months (n = 165), 9 months (n = 188), and 18 months (n = 171) the motor composite scores were 97, 98, and 104, respectively. A motor composite score of ≤-2 SD was only seen in 2.4%, 0%, and 2.3%, respectively, with gross motor deficits being observed more often than fine motor deficits (12% vs. 0% at 18 months). Over 90% of infants who scored average at 9 months still did so at 18 months. The majority of infants with below-average gross motor scores (≤-1) at 9 months still had a below-average or delayed motor score (≤-2 SD) at 18 months. Abnormal gross motor scores (≤-2 SD) increased with age. Infants with single-ventricle physiology performed significantly (p ≤ 0.05) worse on both fine and gross motor skills at 9 and 18 months compared to infants with other CCHDs.

Early Determinants of Adverse Motor Outcomes in Preschool Children with a Critical Congenital Heart Defect.

Neurodevelopmental disabilities are common in infants with critical congenital heart disease (CCHD). A prospective, longitudinal cohort study was conducted to establish the prevalence and early determinants of adverse motor outcomes in infants who underwent cardiac surgery with cardiopulmonary bypass before six months of age. Motor development was assessed in 147 preschoolers using the Movement Assessment Battery for children-II. Although the majority displayed an average motor development, 22% of preschool children with CCHD deteriorated in their motor developmental score compared to their previous assessment at 18 months, especially in those with an aortic arch anomaly (AAA) (35%). Individual stability over time appeared to be moderate and the number of children with a motor delay increased, up to 20% in children with AAA. Motor development up to 42 months was best predicted by gestational age, cardio pulmonary bypass time, aortic cross clamp time, number of heart catheterizations up to 18 months and early motor outcomes. The increase in number of preschool children with a motor delay underlines the importance of longitudinal screening of motor skills in children with CCHD at risk for adverse motor outcomes. Offering early interventions may protect their current and future cardiovascular health as motor development is an independent predictor of exercise capacity, physical activity and participation in daily living.

The Utrecht approach to exercise in chronic childhood conditions: the decade in review.

PURPOSE: To summarize and discuss current evidence and understanding of clinical pediatric exercise physiology focusing on the work the research group at Utrecht and others have performed in the last decade in a variety of chronic childhood conditions as a continuation of the legacy of Dr Bar-Or. KEY POINTS: The report discusses current research findings on the cardiopulmonary exercise performance of children (and adolescents) with juvenile idiopathic arthritis, osteogenesis imperfecta, achondroplasia, hemophilia, cerebral palsy, spina bifida, cystic fibrosis, and childhood cancer. Exercise recommendations and contraindications are provided for each condition. Implications for clinical practice and future research in this area are discussed for each of the chronic conditions presented. CLINICAL IMPLICATIONS: The authors provide a basic framework for developing an individual and/or disease-specific training program, introduce the physical activity pyramid, and recommend a core set of clinical measures to be used in clinical research.

Motor function impairment is an early sign of CLN3 disease.

OBJECTIVE: To delineate timing of motor decline in CLN3 disease. METHODS: Motor function, assessed by the 6-Minute Walk Test (6MWT), was evaluated repeatedly in 15 patients with CLN3 disease, resulting in 65 test results and during one occasion in 2 control cohorts. One control cohort (n = 14) had isolated visual impairment; a second cohort (n = 12) exhibited visual impairment in combination with neurologic impairments. Based on 6MWT reference values in healthy sighted children, z scores of 6MWT results in patients with CLN3 disease and control cohort individuals were calculated. 6MWT results were correlated with age-including multilevel modeling analysis allowing assessment of imbalanced repeated measurements-and with Unified Batten Disease Rating Scale (UBDRS) scores. RESULTS: In CLN3 disease, 6MWT scores were already impaired from first testing near diagnosis (mean z scores of -3.6 and -4.7 at 7 and 8 years of age, respectively). Afterwards, 6MWT scores continuously declined with age (r = -0.64, p < 0.0001) and with increasing UBDRS scores (r = -0.60, p = 0.0001), confirming correlation with disease progression. The decrease was more pronounced at a later age, as shown by the nonlinear multilevel model for 6MWT results in CLN3 disease (y = 409.18 - [0.52 × age2]). In contrast, an upward trend of 6MWT scores with age was observed in the control cohort with isolated visual impairment (r = 0.56; p = 0.04) similar to healthy, sighted children. The control cohort with additional neurologic impairments displayed a slightly decreased 6MWT walking distance independent of age. CONCLUSIONS: The 6MWT unveils early onset of motor decline in CLN3 disease.

Physical training in children with osteogenesis imperfecta.

OBJECTIVE: To study the effects of a physical training program on exercise capacity, muscle force, and subjective fatigue levels in patients with mild to moderate forms of osteogenesis imperfecta (OI). STUDY DESIGN: Thirty-four children with OI type I or IV were randomly assigned to either a 12-week graded exercise program or care as usual for 3 months. Exercise capacity and muscle force were studied; subjective fatigue, perceived competence, and health-related quality of life were secondary outcomes. All outcomes were measured at baseline (T = 0), after intervention (T = 1), and after 6 and 9 months (T = 2 and T = 3, respectively). RESULTS: After intervention (T = 1), peak oxygen consumption (VO2peak), relative VO2peak (VO2peak/kg), maximal working capacity (Wmax), and muscle force were significantly improved (17%, 18%, 10%, and 12%, respectively) compared with control values. Subjective fatigue decreased borderline statistically significantly. Follow-up at T = 2 showed a significant decrease of the improvements measured at T = 1 of VO2peak, but VO2peak/kg, Wmax, and subjective fatigue showed no significant difference. At T = 3, we found a further decrease of the gained improvements. CONCLUSION: A supervised training program can improve aerobic capacity and muscle force and reduces levels of subjective fatigue in children with OI type I and IV in a safe and effective manner.

Reliability of hand-held dynamometry and functional strength tests for the lower extremity in children with Cerebral Palsy.

PURPOSE: To evaluate the intertester reliability of two methods for measuring lower-limb strength in children with cerebral palsy (CP). METHOD: Twenty-five subjects with CP (7-17 years of age) participated in this study. Lower-limb muscle strength was measured on 2 occasions using a Hand-held Dynamometer (HHD; break-method and make-method) and a 30-sec Repetition Maximum (RM) during three functional strength tests for the lower extremities. Reliability was measured using the intraclass correlation coefficients (ICCs), the standard error of measurement (SEM) and the coefficient of variation (CV). RESULTS: The intertester reliability of strength measurement using a HHD was questionable with ICC values ranging from 0.42-0.73 for the break-method, and from 0.49-0.82 for the make-method. The SEM and CV (%) values ranged from 27.9-58.9 and 22.2-35.3% for the break-method, and from 30.6-52.7 and 16.2-56.2% for make-method. The intertester reliability of strength measurement using the 30-sec RM was acceptable with ICC values ranging from 0.91 -0.96, and SEM and CV (%) values ranging from 1.1-2.6 and 10.9-39.9% for the functional exercises. CONCLUSION: The intertester reliability of measuring muscle strength of the lower extremities using a hand-held dynamometer is questionable. The intertester reliability of the 30-sec RM for the lower extremity is acceptable.