Feasibility and reliability of quantifying passive muscle stiffness in young children by using shear wave ultrasound elastography.

OBJECTIVES: The purpose of this study was to investigate the feasibility and reliability of passive muscle stiffness measurements in children by shear wave ultrasound elastography. METHODS: We conducted a prospective cross-sectional study quantifying the passive stiffness of bilateral lateral gastrocnemius muscles during passive stretching in 20 typically developing children (age range, 2.0-12.6 years). Data collected included passive stiffness of the lateral gastrocnemius muscle (shear modulus in kilopascals) at 4 positions of progressive passive foot dorsiflexion, demographic characteristics of the participants, and comparison of demographic characteristics with the shear modulus. RESULTS: Passive stiffness increased with increasing stretching (mean [SD] range of stiffness, 7.1 [2.0] to 36.2 [22.0] kPa). For all 4 foot positions, no significant difference was found between right and left legs (range, P = .42 to P = .98) or between the sexes (range, P = .28 to P > .99). No correlation of passive muscle stiffness with age, body mass index, or ankle range of motion was found. The reliability of measurements was good to excellent (mean [95% confidence interval] range of reliability, 0.67 [0.44-0.83] to 0.80 [0.63-0.90]). CONCLUSIONS: Measurements of passive stiffness of the lateral gastrocnemius muscle are feasible and reliable in children as young as 2 years. Because this study found no significant difference between sex and the side tested in this age group, future studies involving children of this age range may not need to be stratified on the basis of these parameters. Defining normal passive muscle stiffness in children is critical for identifying and understanding the implications of abnormal passive muscle stiffness in children with neuromuscular disorders.

Sonographically guided obturator internus injections: techniques and validation.

OBJECTIVES: The primary purpose of this investigation was to describe and validate sonographically guided techniques for injecting the obturator internus (OI) muscle or bursa using a cadaveric model. METHODS: A single experienced operator completed 10 sonographically guided OI injections in 5 unembalmed cadaveric pelvis specimens (4 female and 1 male, ages 71-89 years with body mass indices of 15.5-24.2 kg/m2). Four different techniques were used: (1) OI tendon sheath (4 injections), (2) OI intramuscular (2 injections), (3) OI bursa trans-tendinous (2 injections), and (4) OI bursa short-axis (2 injections). In each case, the operator injected 1.5 mL of diluted yellow latex using direct sonographic guidance and a 22-gauge, 87.5-mm (3½-in) needle. Seventy-two hours later, study coinvestigators dissected each specimen to assess injectate placement. RESULTS: All 10 OI region injections accurately placed latex into the primary target site. Two of the 4 OI tendon sheath injections produced overflow into the underlying OI bursa. Both OI intramuscular injections delivered 100% of the latex within the OI. All 4 OI bursa injections (2 trans-tendinous and 2 short-axis) delivered 100% of the latex into the OI bursa, with the exception that 1 OI bursa trans-tendinous injection produced minimal overflow into the OI itself. No injection resulted in injury to the sciatic nerve or gluteal arteries, and no injectate overflow occurred outside the confines of the OI or its bursa. CONCLUSIONS: The results of this investigation demonstrate that sonographically guided injections into the OI or its bursa are feasible and, therefore, may play a role in the diagnosis and management of patients presenting with gluteal and "retrotrochanteric" pain syndromes.

Managing Chronic Pain in Children and Adolescents: A Clinical Review.

Chronic pain in children and adolescents can be difficult for a single provider to manage in a busy clinical setting. Part of this difficulty is that pediatric chronic pain not only impacts the child but also the families of these children. In this review article, we discuss etiology and pathophysiology of chronic pain, along with variables that impact the severity of chronic pain and functional loss. We review diagnosis and management of selected chronic pain conditions in pediatric patients, including headache, low back pain, hypermobility, chronic fatigue, postural orthostatic tachycardia syndrome, abdominal pain, fibromyalgia, and complex regional pain syndrome. For each condition, we create a road map that contains therapy prescriptions, exercise recommendations, and variables that may influence pain severity. Potential medications for these pain conditions and associated symptoms are reviewed. A multidisciplinary approach for managing children with these conditions, including pediatric pain rehabilitation programs, is emphasized. Lastly, we discuss psychological factors and interventions for pediatric chronic pain and potential complementary and alternative natural products and interventions.

Physical activity in children and adolescents.

After obesity rates in youth reached alarming rates, public health officials recognized the need for specific physical activity guidelines for children and adolescents. Numerous health care groups and sports and fitness organizations collaborated on the development of the Physical Activity Guidelines for Americans in 2008, which have been widely endorsed and include recommendations for the pediatric population. Children and adolescents should participate in moderate-to-vigorous physical activity 1 or more hours per day and muscle and bone-strengthening activities 3 or more times per week. Physical activities should be age appropriate, enjoyable, and varied and occur beyond what is required for typical activities of daily living. Adequate exercise in youth improves strength, cardiorespiratory fitness, and body composition and therefore decreases cardiovascular risk factors. An improved cardiovascular profile provides a continued benefit in adulthood. Exercise also improves bone health, psychological well-being, cognition, and school performance and may decrease the risk of sports injury. Exercise habits established in childhood often continue into adulthood.