**2.5 Healthy children**

Muscle SWE studies in healthy children are important for the reliability and repeatability of the measurement methods and to understand the effect of some individual factors such as sex and age on muscle stiffness. Brandenburg et al. reported that sex, age, BMI, extremity dominancy, and calf circumference were not associated with muscle stiffness in children [42]. Liu et al. compared the gastrocnemius medialis muscle stiffness of different age groups and found that there was no significant difference between sexes and muscle stiffness was the greatest in the older group, followed by the middle-aged group and then the children group [43]. Although these two studies give some clues, we think that further muscle SWE studies in healthy children are required and these studies are important especially for the measurement reliability, standardization of the measurement method, and establishing norm values for muscle stiffness. Additional information on muscle SWE studies in healthy children is provided in **Table 7**.


*Use of Shear Wave Elastography in Pediatric Musculoskeletal Disorders DOI: http://dx.doi.org/10.5772/intechopen.102063*

*GM, gastrocnemius medialis; GL, gastrocnemius lateralis; DF, dorsi flexion; PF, plantar flexion; BMI, body mass index; R, right; L, left; kPa, kilopascal.*

**Table 7.**

*Studies using muscle shear-wave elastography in healthy children.*

## **3. Conclusions**

Muscle SWE is an exciting and rapidly evolving US technique that allows quantification of muscle stiffness with a non-invasive, non-painful, and non-irradiating examination. It has the potential of wider clinical use because it is relatively low-cost, it provides real-time measurement, it takes less time, especially for the pediatric population, and it is sedation/anesthesia-free. SWE shows promise as an adjunct clinical tool for differentiating between normal and abnormal muscles, monitoring the effectiveness of therapeutic interventions, altering the therapeutic intervention, or deciding treatment duration. Therefore, SWE, which measures individual muscle stiffness, can provide significant benefits, especially for physiotherapists because many rehabilitation strategies aim to change muscle structure. However, some remarkable points such as the insufficient number of studies, the small sample size, the differences in measurement settings and methods between studies, and the lack of norm values for different muscles indicate the necessity for further studies.
