The Comparison of the Effects of Three Physiotherapy Techniques on Hamstring Flexibility in Children: A Prospective, Randomized, Single-Blind Study

Dariusz Czaprowski,Justyna Leszczewska,Piotr Janusz,Agnieszka Kędra,Aleksandra Kolwicz,Tomasz Kotwicki,Paulina Pawłowska,Steve Milanese

doi:10.1371/journal.pone.0072026

Abstract

The aim of the study was to evaluate changes in hamstring flexibility in 120 asymptomatic children who participated in a 6-week program consisting of one physiotherapy session per week and daily home exercises. The recruitment criteria included age (10–13 years), no pain, injury or musculoskeletal disorder throughout the previous year, physical activity limited to school sport. Subjects were randomly assigned to one of the three groups: (1) post-isometric relaxation – PIR (n = 40), (2) static stretch combined with stabilizing exercises – SS (n = 40) and (3) stabilizing exercises – SE (n = 40). Hamstring flexibility was assessed with straight leg raise (SLR), popliteal angle (PA) and finger-to-floor (FTF) tests. The examinations were conducted by blinded observers twice, prior to the program and a week after the last session with the physiotherapist. Twenty-six children who did not participate in all six exercise sessions with physiotherapists were excluded from the analysis. The results obtained by 94 children were analyzed (PIR, n = 32; SS, n = 31; SE, n = 31). In the PIR and SS groups, a significant (P<0.01) increase in SLR, PA, FTF results was observed. In the SE group, a significant (P<0.001) increase was observed in the SLR but not in the PA and FTF (P>0.05). SLR result in the PIR and SS groups was significantly (P<0.001) higher than in the SE group. As far as PA results are concerned, a significant difference was observed only between the SS and SE groups (P = 0.014). There were no significant (P = 0.15) differences regarding FTF results between the three groups. Post-isometric muscle relaxation and static stretch with stabilizing exercises led to a similar increase in hamstring flexibility and trunk forward bend in healthy 10–13-year-old children. The exercises limited to straightening gluteus maximus improved the SLR result, but did not change the PA and FTF results.

Highlights

Reduced hamstring flexibility is a common clinical finding in adolescents [1,2,3]
The aim of the study was to compare the effects of three physiotherapy techniques based on different mechanisms of influencing the musculoskeletal system: (1) post-isometric relaxation - PIR, (2) static stretch combined with stabilizing exercises static stretching (SS) and (3) stabilizing exercises only – SE, on hamstring flexibility following a 6-week exercise program
Before the exercise program there were no differences between the PIR, SS and SE groups regarding age, height, weight, BMI, straight leg raise (SLR), popliteal angle (PA), and FTF (Table 1)

Summary

Introduction

Reduced hamstring flexibility is a common clinical finding in adolescents [1,2,3]. Brodersen et al observed that 75% of boys and 35% of girls aged 10 revealed reduced flexibility of hamstrings [1]. Various stretching techniques are used in clinical practice to increase hamstring flexibility [13,14,15,16,17,18,19,20]. Post-isometric relaxation is considered to be an effective method of increasing hamstring flexibility [23,24,25]

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Conclusion