Shear modulus of lower limb muscles in school-aged children with mild hypotonia.

The objective of this study is to compare shear modulus of lower limb muscles between children with hypotonia versus typical development (TD) or developmental disorders associated with altered tone. Nineteen children with mild hypotonia (mean age 9.4 ± 2.3y, 13 male) completed assessment of resting shear modulus of rectus femoris, biceps femoris (BF), tibialis anterior (TA) and gastrocnemius lateralis (GL) at short and long lengths using shear wave elastography. Data was compared with previous data from TD children and a scoping review for children with developmental disorders. Data were collated according to Net-Longitudinal Tension Angle (Net-LTA), which is the muscle length expressed as the net proximal and distal joint angles. Effects of Net-LTA (e.g., short, neutral, long) were examined according to sex, age and body mass index (BMI). In children with hypotonia, shear modulus was: higher at longer versus shorter lengths for four muscles (p < 0.01); correlated with age for BF-short (r = 0.60, p < 0.03) and GL-short (r = -0.54, p < 0.03), with BMI for BF-short (r = 0.71, p < 0.05); and not different between sexes (p > 0.05). The shear modulus values for lower limb muscles for children with mild hypotonia were lower than those for children with Duchenne Muscular Dystrophy (TA-neutral), or Cerebral Palsy (GL-neutral), but not TD children (all four muscles). In conclusion, shear modulus increases with longer muscle length (i.e. higher Net-LTA) in mildly hypotonic children. Children with mild hypotonia have lower shear modulus than children with cerebral palsy and Duchenne muscular dystrophy.

A profile of reference data for shear modulus for lower limb muscles in typically developing children.

BACKGROUND: Shear wave elastography can measure shear wave speed in muscles, which is used to estimate shear modulus. Normative values and standardized methodology are needed for children. Study aims were to: estimate shear modulus behavior of lower limb muscles of typically developing children; and establish a profile of reference data and recommendations for clinical assessment. METHODS: Forty-one typically developing children (mean 9.7 y, SD 1.9 y) completed assessment of resting shear modulus of rectus femoris, biceps femoris, gastrocnemius lateralis and tibialis anterior at short and long lengths using shear wave elastography. Effects of muscle length, age, sex and BMI were examined. Then, our data and data from a scoping review for typical individuals were collated according to Net-Longitudinal Tension Angle (net proximal and distal joint angles). FINDINGS: Shear modulus was: higher at long versus short muscle lengths for all four muscles (P < 0.001); correlated with increasing age for tibialis anterior at short (r = 0.39) and long lengths (r = 0.42) (both P = 0.01); but not related to sex or BMI. Shear modulus: tended to increase with increasing Net-Longitudinal Tension Angle for 18 lower limb muscles; and was higher for children than adults for some muscles (e.g. tibialis anterior and gastrocnemius lateralis, both P < 0.001). INTERPRETATION: In typically developing children, shear modulus of lower limb muscles increases with increasing Net-Longitudinal Tension Angle. Recommendations enable comparison of values across different test positions and populations. Some relation between shear modulus and age was identified, but more research is needed.

Systematic Review of Instrumented Measures of Skeletal Muscle Mechanical Properties: Evidence for the Application of Shear Wave Elastography with Children.

The aim of this review was to identify instrumented devices that quantify skeletal muscle mechanical properties and to evaluate their potential clinical utility and clinimetric evidence with respect to children. Four databases were searched to identify articles reporting original clinimetric data for devices measuring muscle stiffness or elastic modulus, along a muscle's main fibre direction. Clinimetric evidence was rated using the Consensus-Based Standard for the Selection of Measurement Instruments (COSMIN) checklist. Sixty-five articles provided clinimetric data for two devices meeting our criteria: the Aixplorer and the Acuson. Both are shear wave elastography devices that determine the shear modulus of muscle tissue. The Aixplorer had strong construct validity and reliability, and the Acuson, moderate construct validity and reliability. Both devices have sound clinical utility with non-invasive application at various joint positions and data acquisition in real time, minimizing fatigue. Further research is warranted to evaluate utility for children with specific disorders of abnormal muscle structure or function.

Muscle tone assessments for children aged 0 to 12 years: a systematic review.

AIM: The aim of this study was to identify and examine the psychometric properties of muscle tone assessments for children aged 0 to 12 years. METHOD: Four electronic databases were searched to identify studies that included assessments of resting and/or active muscle tone. Methodological quality and overall psychometric evidence of studies were rated using the COnsensus-based Standards for the selection of health Measurement INstruments checklist. RESULTS: Twenty-one assessments were identified from 97 included studies. All assessments were broad developmental assessments that included muscle tone items or subscales. Most assessments (16/21) were designed for young children (<2y). Four assessments measured resting and active tone and demonstrated at least moderate validity or reliability: the Amiel-Tison Neurological Assessment (ATNA) at term, Neonatal Intensive Care Unit Network Neurobehavioral Scale (NNNS), Premie-Neuro for newborn infants, and the Hammersmith Infant Neurological Examination (HINE) for infants aged 2 months to 2 years. For children over 2 years, the Neurological Sensory Motor Developmental Assessment (NSMDA) assesses resting and active tone but has limited validity. INTERPRETATION: The ATNA at term, NNNS, Premie-Neuro, HINE, and NSMDA can assess resting and active tone in infants and/or children. Further psychometric research is required to extend reliability, validity, and responsiveness data, particularly for older children. WHAT THIS PAPER ADDS: This is the first review of muscle tone assessments for children aged 0 to 12 years. Twenty-one assessments contain muscle tone items and 16 are for children under 2 years. Four assessments are reliable or valid to measure both resting and active tone.

The ratio of change in muscle thickness between superficial and deep cervical flexor muscles during the craniocervical flexion test and a suggestion regarding clinical treatment of patients with musculoskeletal neck pain.

[Purpose] The purpose of this study was to identify the imbalance of muscle recruitment in cervical flexor muscles during the craniocervical flexion test by using ultrasonography and to propose the optimal level of pressure in clinical craniocervical flexion exercise for people with neck pain. [Subjects and Methods] A total of 18 students (9 males and 9 females) with neck pain at D University in Gyeongsangbuk-do, South Korea, participated in this study. The change in muscle thickness in superficial and deep cervical flexor muscles during the craniocervical flexion test was measured using ultrasonography. The ratio of muscle thickness changes between superficial and deep muscles during the test were obtained to interpret the imbalance of muscle recruitment in cervical flexor muscles. [Results] The muscle thickness ratio of the sternocleidomastoid muscle/deep cervical flexor muscles according to the incremental pressure showed significant differences between 22 mmHg and 24 mmHg, between 24 mmHg and 28 mmHg, between 24 mmHg and 30 mmHg, and between 26 mmHg and 28 mmHg. [Conclusion] Ultrasonography can be applied for examination of cervical flexor muscles in clinical environment, and practical suggestion for intervention exercise of craniocervical flexors can be expected on the pressure level between 24 mmHg and 26 mmHg enabling the smallest activation of the sternocleidomastoid muscle.

Comparison of the effectiveness of balance training using a reaching task between a sitting position and a standing position in the elderly.

[Purpose] The purpose of this study was to compare the effectiveness of balance training using a reaching task between a sitting position and a standing position in the elderly. [Subjects and Methods] The study included 30 elderly women from D city. The subjects were divided into the following two groups, according to the training position: the sitting group (n = 15) and standing group (n = 15). Both groups performed training for 20 min, thrice a week for 8 weeks. The short form of the berg balance scale (SFBBS), timed 10-m walk test (10MWT), timed up & go test (TUG), and falls efficacy scale (FES) were used before and after training. [Results] SFBBS, 10MWT, and TUG values were significantly different between before and after training in both groups. However, FES values were significantly different in only the standing group. [Conclusion] Balance training in a standing position is helpful for improving activities that mainly use the lower extremities, such as gait, and training in a sitting position is somewhat helpful for improving balance ability. In addition, balance training in both positions can help overcome the fear of falling.