The effect of hip flexion angle on muscle elongation of the hip adductor muscles during stretching

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 shoulder position during static stretching on shear elastic modulus of biceps brachii muscle

Biceps brachii muscle consists of a long head (BBL) and a short head (BBS). Shortening the BBL and BBS causes tendinopathy of the intertubercular groove and coracoid process. Therefore, it is necessary to stretch the BBL and BBS separately. This study aimed to determine the positions where the BBL and BBS were most stretched, using shear wave elastography (SWE). Fifteen healthy young males participated in the study. The shear elastic moduli of the BBL and BBS of the non-dominant arm were measured using SWE. The measurement positions were the resting position (shoulder flexion and abduction 0°) and four stretching positions.. The elbow was extended, and the forearm was pronated in all positions. Statistical analysis was performed using Wilcoxon's signed-rank test to compare the shear elastic moduli between the resting and stretched limb positions. In addition, Wilcoxon's signed-rank test was used to compare shear elastic moduli between the stretching positions that were significantly different compared to the resting position.. Results show that for BBL and BBS, shear elastic moduli were significantly higher in the shoulder extension + external rotation and shoulder horizontal abduction + internal rotation positions than in the resting position. Moreover, the shear elastic modulus of the BBL was significantly higher in shoulder extension + external rotation than in shoulder horizontal abduction + internal rotation. In contrast, the shear elastic modulus of the BBS was significantly higher in shoulder horizontal abduction + internal rotation than in shoulder extension + external rotation. The BBL and BBS were effectively stretched by shoulder extension + external rotation and horizontal abduction + internal rotation.

Quantifying the shear modulus of the adductor longus muscle during hip joint motion using shear wave elastography

The present study aims to assess the effect of the hip flexion angle on the shear modulus of the adductor longus (AL) muscle associated with passive hip abduction and rotation. Sixteen men participated in the study. For the hip abduction task, the hip flexion angles used were - 20, 0, 20, 40, 60, and 80°, and the hip abduction angles were 0, 10, 20, 30, and 40°. For the hip rotation task, the hip flexion angles used were - 20, 0, 20, 40, 60, and 80°, hip abduction angles were 0 and 40°, and hip rotation angles were 20° internal rotation, 0° rotation, and 20° external rotation. The shear modulus at 20° extension was significantly higher than that at 80° flexion for the 10, 20, 30 and 40° hip abduction (i.e., P < 0.05). The shear modulus at 20° internal rotation and 20° extension was significantly higher than that at 0° rotation and 20° external rotation, regardless of the hip abduction angle (i.e., P < 0.05). The mechanical stress of the AL muscle associated with hip abduction was higher in the extended position. Furthermore, the mechanical stress could increase with internal rotation only at the hip-extended position.

Is there a correlation between the femoral anteversion angle and the elasticity of the hip muscles in cases of intoeing gait due to increased femoral anteversion angle?

Purpose

One of the common causes of gait disturbance in children is increased femoral anteversion. There are not enough publications in the literature on muscles related to the hip joint in increased femoral anteversion. The aim of this study was to evaluate the relationship between the femoral anteversion angle and hip muscle elasticity in children walking inward, using shear wave elastography (SWE).

Material and methods

Seventeen children with bilateral increased femoral anteversion angle in computed tomography were prospectively included in this study. Elasticity values of the hip muscles (adductor magnus (adductor), iliopsoas (flexor), gluteus medius (abductor), gluteus maximus (extensor) muscles) were evaluated by ultrasound elastography by two observers. Quantitative measurements of the shear wave velocities were performed using virtual touch tissue imaging quantification.

Results

There was excellent harmony between the femoral anteversion angle measurements performed by the two observers and a good congruence between the muscle elastography evaluations. While there was a moderate significant correlation between the femoral anteversion angle and the elasticity values of the iliopsoas and adductor magnus muscles, no significant correlation was found with other muscle elasticity measurements.

Conclusion

Iliopsoas muscle and adductor magnus muscle elasticity are correlated with the femoral anteversion angle. With further studies, we think that physical therapy methods for the elasticity of the muscles associated with the femoral anteversion angle can reduce the complaints of the patients.

Adductor longus: An anatomical study to better understand groin pain

INTRODUCTION

We investigated the shear modulus-passive force relationship in the hip adductor longus (AL) muscles of human cadavers and explored the effect of muscle architecture on the elastic properties of the AL muscle using shear wave elastography (SWE).

MATERIALS AND METHODS

Nine AL muscles were harvested from a soft, embalmed cadaver. The AL muscles were affixed to a custom-built device comprising two clamps, a pulley, and a cable to provide passive loads, which were increased from 0 to 600 g in 60-g increments. The shear modulus of the AL muscle was measured in the proximal (Pro), middle (Mid), and distal (Dis) regions. The masses and anatomical cross-sectional areas (ACSAs) of the AL muscles were measured. The shear modulus-passive load relationship of each tested muscle region was analyzed by fitting a least-squares regression line. Moreover, the rate of increase in the shear modulus per unit load (s) was calculated.

RESULTS

The shear modulus and passive force were linearly correlated for all AL muscles in each region (P<0.01). The mean coefficients of determination (R² ) for Pro, Mid, and Dis were 0.989, 0.986, and 0.982, respectively. The rate of increase in the shear modulus per unit load significantly correlated with the reciprocal of the muscle mass (r=0.77, P=0.02) and ACSA (r=0.43, P=0.03).

CONCLUSION

Shear wave elastography can be used as an indirect measure of passive force in any region of the AL muscle. Additionally, the rate of increase in the shear modulus per unit load could be associated with muscle architectural parameters. This article is protected by copyright. All rights reserved.

Effective muscle elongation positions for the neck extensor muscles: An ultrasonic shear wave elastography study

This study aimed to clarify the effective stretching positions for neck extensor muscles. Fifteen healthy men were measured shear moduli of the right neck extensor muscles using ultrasound shear wave elastography in following positions: rest (Rest), flexion (Flex), contralateral bending (Bend), flexion + contralateral bending (Flex → Bend), flexion + contralateral bending + contralateral rotation (Flex → Bend → ConRot), and flexion + contralateral bending + ipsilateral rotation (Flex → Bend → IpsRot). The increase in the shear modulus indicated a greater muscle elongation. Regarding the upper trapezius and splenius capitis, the shear moduli at Flex → Bend, Flex → Bend → ConRot, and Flex → Bend → IpsRot were significantly higher than those at Rest. The shear moduli at stretching positions, including contralateral bending, were significantly higher than those at Rest and Flex in the levator scapulae. The results indicated that the stretching position with a combination of flexion and contralateral bending could be effective for elongation of the upper trapezius and splenius capitis. Furthermore, the stretching positions including contralateral bending could be effective for the levator scapulae.

Differences in shear elastic modulus of the latissimus dorsi muscle during stretching among varied trunk positions

The latissimus dorsi (LD) can be divided into the upper, middle, and lower parts, but the effective stretching positions for each part are unknown. In this study, we aimed to investigate effective trunk positions for stretching of the LD. A total of 14 healthy males participated in this study. The following seven trunk positions were chosen as the LD stretching positions; upright of the trunk (Baseline), flexion of the trunk (Flex), contralateral bending of the trunk (LB), contralateral rotation of the trunk (Rot), flexion and contralateral bending of the trunk (Flex + LB), flexion and contralateral rotation of the trunk (Flex + Rot), and contralateral bending and contralateral rotation of the trunk (LB + Rot). Maximal elevation of the upper limb was passively added to all positions. The shear elastic modulus, used as the index of muscle elongation, was measured at the four parts (upper, middle, lower, distal parts) of the LD. The shear elastic moduli showed obviously high values in Rot and LB + Rot at the upper, middle, and distal parts, and also in LB, Rot, and LB + Rot at the lower part. These findings suggest that contralateral trunk rotation, or a combination of contralateral trunk bending and rotation are effective trunk positions for stretching all parts of the LD. Contralateral trunk bending was also effective for stretching the lower part of the LD.