# Movement Analysis for Health and Biometrics
## 3 Movement Analysis for Injury Prevention  
The analysis of movement can be exploited to prevent a variety of injuries, as for example those caused by falls, poor movement control, and bad postures [11]. In fact, the possibility of estimating forces at joints by tracking movement, as well as evaluating muscular performance, allows the definition of training programs aimed at correcting postures, movement control and improving sports performance. The Special Issue includes six contributions that investigate the use of movement analysis to prevent injuries. [PERSON] et al. [12] assess the relationship between two movement screening tools in youth football (soccer) players, which suffer from knee injuries caused by poor movement control in the hip and pelvic region. The Functional Movement Screen (FMS) is the most well-known movement screening tool, designed to assess mobility and stability within the whole-body kinetic chain, but it is not useful to assess the functional status of hip dysfunction. The Hip and Lower Limb Movement Screen (HLLMS) was designed to detect altered movement patterns and asymmetry, specifically of the hip, pelvis and lower limbs. The study includes 41 elite male football players. The correlation between HLLMS and FMS scores is evaluated with [PERSON]'s rank correlation. The study shows that the two tools assess different aspects of movement quality in healthy youth football players. In fact, only 2 out of 7 tasks of FMS are moderately related to the HLLMS score, while the other FMS tasks are weakly related or unrelated to the HLLMS. [PERSON] et al. [13] investigate the efficacy of digital human modeling technologies when used as ergonomics analysis tools to simulate body postures and estimate the risk of work-related musculoskeletal disorders. In particular, the authors evaluate the accuracy of a commercial full-body dynamic simulator in estimating the posture of subjects that pushed and pulled a 40 kg load and the resulting compressive and anterior/posterior shear force at the L4/L5 lumbar spine. The authors compare the postures estimated by the simulator to the actual human movements captured by a motion tracking system. Their analysis shows that joint angle deviations directly led to a significant difference in the estimated forces. Furthermore, it shows that individual factors (such as body height, body weight, trunk and hip flexion, shoulder movement, and muscle strength between genders) directly affect the adopted postures during task execution. As a consequence, these factors must be taken into account by full-body software simulators to perform a robust ergonomics analysis. [PERSON] et al. [14] investigate the effect of a change of direction on whole-body coordination and stepping in healthy old and young adults. Turning kinematics and stepping variables are recorded using Inertial Measurement Units when subjects execute standing turns on level ground at three different amplitudes and at their own pace. The authors notice that an increase in turn amplitude causes changes in turning kinematics, stepping characteristics, and turning speeds both in young and old adults. However, step duration and turn speed do not significantly differ between the two groups. The results of the study suggest that turning amplitude is a critical factor for the maintenance of balance and stepping movement control. Consequently, it must be taken into account when the turning characteristics of elderly people are assessed to evaluate the risk of falling or when exercises for fall prevention are designed. [PERSON] et al. [15] evaluate the impact of whole-body cryotherapy, a treatment used in prevention and post-injury therapy, on the risk of injury in trained subjects. The authors compare the bioelectric activity of the rectus femoris muscle, measured with surface electromyography, and the parameters of the countermovement jump test, measured with an inertial sensor. The study involves 24 subjects executing vertical jumps before and after a 3 min long whole-body cryotherapy.