The Influence of Self-Stretching Based on Postisometrical Relaxation, Static Stretching Combined with Stabilizing Exercises, and Stabilizing Exercises Only on the Flexibility of One-Joint and Two-Joint Hip Flexors

Background and Objective. The limitations of muscle flexibility are a common dysfunction of the musculoskeletal system. Therefore, various therapeutic techniques are used in rehabilitation programs to increase their flexibility. The aim of this prospective, randomized, single-blind study was to evaluate the changes in the flexibility of hip flexors in children who participated in a 6-week therapeutic program consisting of one physiotherapy session per week with a physiotherapist and daily home exercises.
Material and Methods. A total of 94 children aged 10–13 years were randomly assigned to 3 experimental groups: postisometrical relaxation group (PIR group), static stretching combined with stabilizing exercise group (SE/SS group), and stabilizing exercise group (SS group). To assess the flexibility of one- and two-joint hip flexors, the modified Thomas test was used. The examination was conducted by blinded observers.
Results. A significant improvement in the flexibility of one-joint hip flexors was documented in all 3 groups (P<0.01). The flexibility of two-joint hip flexors increased significantly only in the SS/SE group (P<0.05). After the program, the highest range of motion of the hip extension (test for one-joint hip flexors) was recorded in the SS/SE group (20.6°±4.5°), and it was significantly greater than in the SE group (16.6°±4.0°, P<0.05). There were no significant differences in the knee flexion (test for two-joint hip flexors) among all 3 groups (P>0.05).
Conclusions. The 6-week therapeutic program regardless of the technique applied (postisometrical muscle relaxation, static stretching with stabilizing exercises, and stabilizing exercises only) resulted in the increased flexibility of one-joint hip flexors. Only static stretching combined with stabilizing exercises led to a significant increase in the flexibility of two-joint hip flexors.