A novel approach to improve hamstring flexibility: A single-blinded randomised clinical trial

Discussing Conflicting Explanatory Approaches in Flexibility Training Under Consideration of Physiology: A Narrative Review

The mechanisms underlying range of motion enhancements via flexibility training discussed in the literature show high heterogeneity in research methodology and study findings. In addition, scientific conclusions are mostly based on functional observations while studies considering the underlying physiology are less common. However, understanding the underlying mechanisms that contribute to an improved range of motion through stretching is crucial for conducting comparable studies with sound designs, optimising training routines and accurately interpreting resulting outcomes. While there seems to be no evidence to attribute acute range of motion increases as well as changes in muscle and tendon stiffness and pain perception specifically to stretching or foam rolling, the role of general warm-up effects is discussed in this paper. Additionally, the role of mechanical tension applied to greater muscle lengths for range of motion improvement will be discussed. Thus, it is suggested that physical training stressors can be seen as external stimuli that control gene expression via the targeted stimulation of transcription factors, leading to structural adaptations due to enhanced protein synthesis. Hence, the possible role of serial sarcomerogenesis in altering pain perception, reducing muscle stiffness and passive torque, or changes in the optimal joint angle for force development is considered as well as alternative interventions with a potential impact on anabolic pathways. As there are limited possibilities to directly measure serial sarcomere number, longitudinal muscle hypertrophy remains without direct evidence. The available literature does not demonstrate the necessity of only using specific flexibility training routines such as stretching to enhance acute or chronic range of motion.

The Effect of Active Release Technique on Hamstring Extensibility: A Critically Appraised Topic

CLINICAL SCENARIO

Hamstring extensibility plays a significant role in maintaining postural alignment essential for a functional musculoskeletal system. When hamstring extensibility is lacking, individuals are placed at a higher risk for developing various lumbar spine, pelvis, knee, and foot dysfunctions. Limited hamstring extensibility is common, occurring in as much as 40% of college students and 86% of the adult population. Therefore, it is essential to maintain hamstring extensibility, which can be aided by understanding intervention effectiveness for improving flexibility.

PURPOSE

To critically appraise the literature on the effectiveness of Active Release Technique (ART) for the treatment of hamstring extensibility deficits.

CLINICAL QUESTION

What is the effect of ART in a healthy population with or without hamstring extensibility deficits?

SUMMARY OF KEY FINDINGS

Three studies were included for critical appraisal. Two studies concluded a single treatment session of ART that individuals possessing limited straight leg raise range of motion experienced improved active knee extension, popliteal angle, and sit-and-reach test measures. In the third study, a single session of ART was effective at improving hamstring extensibility in males without hamstring extensibility dysfunction.

CLINICAL BOTTOM LINE

Based on the current level 1 and level 3 evidence, ART may be an effective treatment to produce acute increases in hamstring extensibility. Future research is still needed.

STRENGTH OF RECOMMENDATION

Level B evidence exists to support the use of ART to improve hamstring extensibility in the healthy population.

Immediate effects of lumbar fascia stretching on hamstring flexibility: A randomized clinical trial

BACKGROUND

The hamstring muscles have a great tendency to decrease their extensibility, a phenomenon that presents a distinct clinical entity called short hamstring syndrome (SHS), in addition to problems with adjacent structures.

OBJECTIVE

The objective of this study was to evaluate the immediate effect of lumbar fascia stretching on the flexibility of the hamstring musculature.

METHODS

A randomized controlled trial was carried out. Forty-one women between 18 and 39 years old were divided into two groups: the experimental group received a technique of fascial stretching in the lumbar area while the control group participated in a magnetotherapy machine that was turned off. Hamstring flexibility in both lower limbs was measured by the straight leg raising test (SLR) and the passive knee extension test (PKE).

RESULTS

The results showed statistically significant improvements (p< 0.05) in the SLR and the PKE for both groups. There was a large effect size (Cohen's d) for both tests. There was a statistically significant correlation between the International Physical Activity Questionnaire (IPAQ) and the SLR.

CONCLUSION

The inclusion of lumbar fascia stretching might be an effective part of a treatment protocol to increase the flexibility of the hamstring muscle observing an immediate result in healthy participants.

Phenomenological physiotherapy: extending the concept of bodily intentionality

This study clarifies the need for a renewed account of the body in physiotherapy to fill sizable gaps between physiotherapeutical theory and practice. Physiotherapists are trained to approach bodily functioning from an objectivist perspective; however, their therapeutic interactions with patients are not limited to the provision of natural-scientific explanations. Physiotherapists' practice corresponds well to theorisation of the body as the bearer of original bodily intentionality, as outlined by Merleau-Ponty and elaborated upon by enactivists. We clarify how physiotherapeutical practice corroborates Merleau-Ponty's critical arguments against objectivist interpretations of the body; particularly, his analyses demonstrate that norms of optimal corporeal functioning are highly individual and variable in time and thus do not directly depend on generic physiological structures. In practice, objectively measurable physical deviations rarely correspond to specific subjective difficulties and, similarly, patients' reflective insights into their own motor deficiencies do not necessarily produce meaningful motor improvements. Physiotherapeutical procedures can be understood neither as mechanical manipulations of patients' machine-like bodies by experts nor as a process of such manipulation by way of instructing patients' explicit conscious awareness. Rather, physiotherapeutical practice and theory can benefit from the philosophical interpretation of motor disorders as modifications of bodily intentionality. Consequently, motor performances addressed in physiotherapy are interpreted as relational features of a living organism coupled with its environment, and motor disorders are approached as failures to optimally manage the motor requirements of a given situation owing to a relative loss of the capacity to structure one's relation with their environment through motor action. Building on this, we argue that the process of physiotherapy is most effective when understood as a bodily interaction to guide patients towards discovering better ways of grasping a situation as meaningful through bodily postures and movements.

Kinematics and Esthetics of Grand Battement After Static and Dynamic Hamstrings Stretching in Adolescents

The objective of this study was to explore the effects of static and dynamic hamstring muscles stretching on kinematics and esthetics of grand battement (high velocity kicks) in adolescent recreational dancers. Sixteen participants were assessed before and immediately after both stretching modalities. Kinematics of movement was measured by an optoelectronic system and esthetics was scored by a jury of professional dancers. Both stretching modalities led to significant kinematic differences compared with without stretching. Significant linear correlations between kinematic parameters and esthetic scores have been observed: improving dancers' physical performances has noticeable impact on the perception of their movements.

Straight Leg Raise Test: Influence of Lumbosant© and Assistant Examiner in Hip, Pelvis Tilt and Lumbar Lordosis

The passive straight leg raise (PSLR) test is widely used to assess hamstring extensibility. However, to accurately measure hamstring extensibility throughout PSLR, appropriate stabilization of the pelvis must be provided in order to minimize the possible influence of any compensatory movement in the scores reached. The main purpose of this study was to demonstrate the degree of influence of the Lumbosant© and an assistant examiner in hamstring extensibility in healthy young adults. A secondary objective was to verify the variability of the posterior pelvic tilt movement. Hamstring muscle extensibility was measured using the traditional (only an examiner) and new (using a low-back protection support Lumbosant© and two trained [principal and assistant] examiners) PSLR procedures. Correlation coefficients were expressed using r values, accompanying descriptors and 90% confidence intervals. Variance explained was expressed via the R2 statistic. To examine possible differences, the Mann-Whitney U-test was conducted. Additionally, Cohen’s d was calculated for all results, and the magnitudes of the effect were interpreted and statistical significance set at p < 0.05. A stepwise multiple regression analysis was performed to examine the relationship between scores and values. The final score that was determined with the new PSLR is significantly lower (13° approximately) than the one obtained through the traditional procedure (75.3 ± 14.4° vs. 89.2 ± 20.8°; d = −0.777 [moderate]). The data presented in this study suggest that the PSLR may overestimate hamstring extensibility unless lumbopelvic movement is controlled. Therefore, we recommend the use of Lumbosant© and an auxiliary examiner to obtain more accurate hamstring extensibility scores.