Effective Stretching Positions of the Piriformis Muscle Evaluated Using Shear Wave Elastography

CONTEXT

Piriformis syndrome is often associated with muscle spasms and shortening of the piriformis muscle (PM). Physical therapy, including static stretching of the PM, is one of the treatments for this syndrome. However, the effective stretching position of the PM is unclear in vivo. This study aimed to determine the effective stretching positions of the PM using ultrasonic shear wave elastography.

DESIGN

Observational study.

METHODS

Twenty-one healthy young men (22.7 [2.4] y) participated in this study. The shear elastic modulus of the PM was measured at 12 stretching positions using shear wave elastography. Three of the 12 positions were tested with maximum internal rotation at 0°, 20°, or 40° hip adduction in 90° hip flexion. Nine of the 12 positions were tested with maximum external rotation at positions combined with 3 hip-flexion angles (70°, 90°, and 110°) and 3 hip-adduction angles (0°, 20°, and 40°).

RESULTS

The shear elastic modulus of the PM was significantly higher in the order of 40°, 20°, and 0° of adduction and higher in external rotation than in internal rotation. The shear elastic modulus of the PM was significantly greater in combined 110° hip flexion and 40° adduction with maximum external rotation than in all other positions.

CONCLUSION

This study revealed that the position in which the PM was most stretched was maximum external rotation with 110° hip flexion and 40° hip adduction.

Effects of ELDOA and post-facilitation stretching technique on pain and functional performance in patients with piriformis syndrome: A randomized controlled trial

BACKGROUND

Piriformis syndrome (PS) is a neuro-muscular condition, which is often underdiagnosed in clinical settings. This study will determine the effects of myofascial stretching Elongation Longitudinaux Avec Decoaption Osteo Articulaire (ELDOA) and post-facilitation stretching of the piriformis muscle in patients with PS.

OBJECTIVE

We aimed to compare the effects of ELDOA and post-facilitation stretching of the piriformis muscle on pain, muscle length and functional performance in patients with PS.

METHODS

A randomized clinical trial was conducted with 40 PS patients including both males and females, between the ages of 30-70. Patients were randomly assigned to the ELDOA or post-facilitation group after assessments with the Numeric Pain Rating Scale (NPRS), Lower Extremity Functional Scale (LEFS), Piriformis Length Test and Straight Leg Raise (SLR). The assessments were done at baseline and at the end of the sixth week of treatment.

RESULTS

The patients treated with ELDOA demonstrated significant improvement in pain (pre = 7.00 ± 2.75, post = 3.00 ± 1.75), piriformis length (pre = 27.6 ± 5.54, post = 36.8 ± 3.13), SLR (pre = 36.40 ± 7.24, post = 67.5 ± 8.36) and LEFS (pre = 26.90 ± 12.24, post = 58.10 ± 8.62), as compared with the group treated with post-facilitation stretching: pain: pre = 6.00 ± 1.00, post = 2.00 ± 1.50; piriformis length: pre = 28.55 ± 4.03, post = 38.8 ± 2.70; SLR: pre = 40.60 ± 7.48, post = 74.25 ± 5.19, and LEFS: pre = 25.20 ± 7.66, post = 66.30 ± 7.27).

CONCLUSION

It can be concluded that the post-facilitation stretching technique shows more improvement in pain, muscle length, SLR, and LEFS in patients with PS as compared to ELDOA.

A new concept for evaluating muscle function in the lower extremities in cases of low back pain syndrome in anamnesis

INTRODUCTION

There are difficulties in objective evaluation of activity of the muscles in the lower extremities of patients after successful treatment of sciatica and pseudosciatica, when no clear clinical symptoms are detected. However, the existence of some muscle dysfunction can be hypothesised and its detection was the aim of the study.

OBJECTIVE

Recordings from chosen lower extremity muscles during standing were performed as supplementary differential diagnosis in evaluation of these patients. EMG in standing positions constitutes a new methodological approach not described in detail.

METHODS

Twenty patients (11 after sciatica and 9 after sciatica-like episodes) were enrolled into the study. On the day of examination, clinical and electroneurographical (ENG; M and F waves tests) studies showed no pathology. The percentage of maximal voluntary contraction (MVC) defined muscle activity during standing. Mean amplitude and number of changes in muscle activity (fluctuations) were measured in surface electromyography recordings (sEMG) during normal standing and tandem positions.

RESULTS AND CONCLUSIONS

Activity of proximal lower extremity muscles expressed as percentage of MVC was bilaterally increased in patients after sciatica in normal standing position, compared with results from the group of healthy volunteers (N=9). Patients after sciatica were also characterized with a significant increase of mean sEMG amplitude, recorded especially in distal muscles on the affected side during tandem position. This pathological change was related to decrease in 'fluctuations' frequency in patients after sciatica (P<0.001) more than after pseudosciatica (P<0.01) groups in both standing positions, compared to parameters of healthy volunteers. Sciatica and pseudosciatica in anamnesis cause different abnormal patterns of lower extremity muscle activity during standing positions when recorded with surface EMG.