Flexibility, also called joint mobility, is the capability of one or a set of joints to move freely throughout their range of mobility. It is therefore closely correlated with the range of motion (ROM) which is defined as the maximum possible amplitude of movement in compliance with the physiologically imposed limits of the joints, tendon and ligament structures and the conformation and physiological action of the muscles involved.

Flexibility is an important quality for an active subject as it contributes to physical well-being by increasing the flow of blood and oxygen throughout the body, maintaining a correct posture, economizing movements, improving sports performance, developing strength, and preventing muscle-tendon-joint injuries. From the performance point of view, joint mobility is an essential component of movement and as such must be developed through an appropriate training program involving a combination of active and passive exercises. Training must be constant as flexibility regresses fairly quickly.

There are many body factors that affect mobility, in particular mobility may depend on the very structure of the joint: elasticity and length of muscles, tendons, ligaments, and skin, and the ability of a muscle to relax and contract are in fact chiefly responsible for any stiffening. External influences are on the other hand due to physiological factors such as ambient and body temperature, time of day, age, gender, and mood.

In general, in order to move effectively and without any particular effort, the ROM must be the maximum for each joint. Maintaining incorrect static postures for long periods of time can lead to feelings of sickness and tiredness: in this case, stretching can be a useful tool for loosening the muscles and restoring elasticity. In addition, an appropriate ROM allows the joint to adapt more easily to the stresses to which the body is subjected and reduces the potential risk of injury and distortion. In sport, it is therefore essential to train this characteristic as well, and the Gyko inertial sensor can be used in a very simple and fast way to monitor joint flexibility and dynamic ROM over time. It provides not only the measurement of the angle, but also information on the fluidity and speed of the movement performed (see Figure). The bands allow positioning it on different regions of the body thus allowing each joint to be measured.

Figure 1 The image shows a screenshot of the GykoRepower software during a test of the articular range of a shoulder. The returned data are the ROM in degrees, the fluidity of the movement, and the speed.

Gyko is also recommended to be used following accidents when it is very often difficult to restore the previous joint situation and it is therefore essential to measure the improvements obtained in terms of degrees, during a rehabilitation process.

Citing the approach of one of the world’s leading exponents of strength training: “Mobility before stability, stability before movement... movement before strength.