Study Protocol

Clinical Relationship between a Hypertonic Psoas Muscle & Hamstring Flexibility

 

​Principle Investigator:  Anita Davidson PT



Background

The relationship between the psoas major and low back pain has been extensively studied and validated in the peer reviewed clinical literature. The literature has focused on the psoas’ impact of limiting or providing stability to the spine, of lumbar pain syndromes, and of the general performance of the psoas during gait. However, the relationship between the psoas muscles and the hamstring musculature flexibility to date have not been studied.  A limited number of studies have been performed related to children with Cerebral Palsy pertaining to the comorbidity of hip flexion and hamstring contractures. However, these studies discuss a neurologic, static relationship of position they do not address the dynamic interactions of the psoas on hamstring flexibility.

This study protocol is designed with a two phase data collection process to more completely assess the cause and effect relationship of a hypertonic psoas and limited hamstring flexibility utilizing a double blinded, randomized study format.13  Phase I will encompass the initial data collection related to the presence of the psoas-hamstring relationship followed by Phase II which will determine the impact of modifying stretching type and order as related to hamstring flexibility.

The study sample population goal is 75 with a volunteer mixed population of men and women, ages ranging from 18-60 with subjective reports of tight hamstrings.