BACKGROUND: The psoas major is an important muscle that is part of the iliopsoas complex, which is also known as the hip flexor and contains a major web of nerves called the lumbar plexus. The location of the lumbar plexus within the psoas muscle has been studied on cadaveric dissections previously, particularly with respect to the location of the L4 nerve root but the effect of posture on psoas morphology has not previously been studied. Hip flexion along with the potential changes in spinal alignment while in an upright sitting position may cause significant changes in the positioning and geometry of the psoas and may also change the orientation of the lumbar plexus within the muscle. Current controversy exists in determining patient suitability for Lateral Lumbar Interbody Fusion (LLIF) based on psoas morphology. Oblique and trans-psoas approaches have become a popular minimally invasive lumbar fusion technique in recent years. Lumbar plexus injury, particularly L4 nerve root injury, is a known potential complication of the oblique and trans-psoas approach and may be minimized by careful assessment of the psoas anatomy preoperatively. Quadriceps weakness as a result of L4 nerve root injury is a known potential complication of the trans-psoas approach and may be minimized by careful assessment of the psoas anatomy preoperatively. Patients may present with a sitting MRI rather than supine MRI, however, the effect of posture on the geometry of the psoas muscle, and therefore of the lumbar plexus, has not been previously reported. METHODS: We conducted a retrospective review of a single-spine surgeon practice over a 6-month period to identify patients who had undergone MRI of the lumbar spine for evaluation of degenerative spinal pathologies. Male and female patients were included if aged between 18-90 years presenting with degenerative lumbar spinal pathology between 2015-2016, and excluded if they had previous lumbar fusion, scoliosis, diagnosed with neuromuscular disease, were skeletally immature or had intrinsic abnormalities of the psoas muscles (e.g. tumor, infection or trauma). The anteroposterior (AP) dimension of the psoas muscle was measured at each disc space from L1 to L5 and compared to the AP dimension of the intervertebral disc, as measured at the inferior vertebral endplate. The AP psoas:disc ratio was then calculated and compared between patients undergoing sitting and/or supine MRIs. RESULTS: With a total of 269 patients, 113 of them were male and 157 were female. 209 patients were identified with supine-, and 60 patients with sitting- MRIs, of which 13 patients had undergone both sitting and supine MRIs (BOTH group). A propensity score match (PSM) was performed for patients undergoing either a supine or sitting MRI to match for age, BMI and gender to produce two groups of 43 patients. In the BOTH and PSM group, the sitting MRIs displayed significantly higher AP psoas:disc ratio compared with the supine MRIs at all intervertebral levels except L1-L2. The largest difference observed was a mean 32-37% increase in sitting AP psoas:disc ratio at the L4-L5 disc in sitting MRIs compared to supine MRIs in the BOTH group (range 0-137%). CONCLUSIONS: The psoas muscle and the lumbar plexus became anteriorly displace in sitting MRIs, with a greater effect noted at caudal intervertebral discs. This may have implication in selection suitability for LLIF and intra-operative patient positioning.

Golf är en komplex sport som ställer höga krav på utövarens rörlighet i framförallt höfter, rygg och axlar. Begränsad rörlighet i dessa delar leder inte sällan till skada. I denna studie undersöktes om det finns något samband mellan höftrörlighet och bålrotation hos 27 professionella golfspelare. Studien innehöll även en interventionsdel där 16 idrottsaktiva män fick sina höfter behandlade med stretching för att se om detta påverkar bålrotationsförmågan. Hypotesen var att det finns ett samband och att stretchning av psoas major ökar bålrotationen. Golfspelarnas medelålder var 29 år (SD ±4 år), de hade olika nationaliteter och spelade aktivt på någon av de ledande golftourerna i världen. Deltagarna i interventionsstudiens medelålder var 30 år (SD ±2 år) och de var bosatta i Stockholm. Höftrörlighet mättes med hjälp av modifierat Thomas test och bålrotation i sittande på brits. Mätverktyget var digital goniometer. Stretchbehandlingen utfördes av testledaren med försökspersonen liggande på brits i samma position som vid modifierat Thomas test. Signifikant korrelation(-0,40) ses mellan bålrotation vänster och höftextension vänster höft hos golfspelarna. Interventionsgruppen ökar sin bålrotation från 68 grader (SD ±9 grader) till 70 grader (SD ±9 grader) till vänster och från 70 grader (SD ±12 grader) till 73 grader (SD ±11 grader) till höger. Båda ökningarna är signifikanta. Vald signifikansnivå α=0,05. Resultatet av denna studie är att bålrotationen kan förbättras genom stretchning av höftens flexorer och att det kan finnas ett samband mellan höftens rörlighet och rotationsförmågan i bålen. Denna kunskap kan vara en hjälp för fysioterapeuter som är verksamma inom idrotter som kräver både god höftrörlighet och bålrotation. / Golf is a complex sport that require great mobility in hips, back and shoulders. Limited mobility in these parts of the body can cause injury. This study is investigating the possible correlation between hip mobility and trunk rotation among 27 professional golf players. The study also includes an intervention group of 16 sport active males that got their hips treated with stretching, to examine possible effects on the trunk rotation. The hypothesis was that there is a correlation and that stretching of psoas major increases the trunk rotation. The average age of the golf players was 29 years (SD±4 years), they were of different nationalities but were all professionally active within one of the leading international golf tours. The participants of the intervention study had an average age of 30 years (SD ±2 years), and were all Stockholm residents. The hip rotation was measured through a modified Thomas test, and the trunk rotation were performed in sitting position on a regular treatment table. The measuring instrument was a digital goniometer. The stretching treatment was done by the test leader with the subjects lying on the treatment table in the same position as when performing the modified Thomas test. Significant correlation (-0.40) is seen between left trunk rotation and left hip extension among the golf players. The intervention group increases their left trunk rotation from 68 degrees (SD ±9 degrees) to 70 degrees (SD ±9 degrees) and from 70 degrees (SD ±12 degrees) to 73 degrees (SD ± 11 degrees) on their right trunk rotation. Both increases are to be considered as significant. Chosen significance level is α=0.05. The result of this study is that the trunk rotation can be improved by stretching of the hip muscles and that there is a plausible correlation between the mobility of the hip and the trunk rotation. This knowledge can be used by physiotherapists that are specialised on sports that requires both good hip mobility and trunk rotation.

No description available.