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Measurement of muscle length-related electromyography activity of the hip flexor muscles to determine individual muscle contributions to the hip flexion torque.

Jiroumaru T, Kurihara T, Isaka T - Springerplus (2014)

Bottom Line: The root mean square (RMS) value for the TFL at 30° (0.81 ± 0.19, p <0.005) and 60° (0.66 ± 0.17, p <0.001) and the SA at 60° (0.62 ± 0.24, p <0.005) were significantly decreased compared with those at 0°.However, the RMS value for the IL and RF did not change significantly.We conclude that, in a hip joint flexed position, the contribution of the IL to hip flexion movement is relatively larger than that of the other hip flexor muscles.

View Article: PubMed Central - PubMed

Affiliation: Graduate School of Sport and Health Science, Ritsumeikan University, 1-1-1 Noji Higashi, Kusatsu, Shiga, 525-8577 Japan ; Shiga School of Medical Technology, 967 Kitasaka-cho, Higashiomi, Shiga, 527-0145 Japan.

ABSTRACT
This study aimed to investigate muscle length-related electromyography (EMG) of the iliopsoas (IL) and other hip flexor muscles to determine individual muscle contributions to the hip flexion torque. Ten healthy sedentary young men participated in the EMG experiment. A subgroup of six subjects underwent a magnetic resonance imaging (MRI) measurement to confirm the region of the skin over the IL. Surface EMG signals were sampled from the IL, rectus femoris (RF), sartorius (SA), and tensor fasciae latae (TFL) using an active electrode. The subjects performed maximum voluntary isometric hip flexion with the right hip joint set at -10°, 0°, 30°, and 60°. The root mean square (RMS) value for the TFL at 30° (0.81 ± 0.19, p <0.005) and 60° (0.66 ± 0.17, p <0.001) and the SA at 60° (0.62 ± 0.24, p <0.005) were significantly decreased compared with those at 0°. However, the RMS value for the IL and RF did not change significantly. The RMS value and muscle length changes were significantly correlated in the IL (r =0.39, p <0.05), SA (r =0.51, p <0.001), and TFL (r =0.70, p <0.001), but not in the RF (r =0.22, p =0.180). We conclude that, in a hip joint flexed position, the contribution of the IL to hip flexion movement is relatively larger than that of the other hip flexor muscles.

No MeSH data available.


Confirmation of the electrode positions. (a) Electrode positions on the hip flexor muscles. Representative maximal perimeter IL, 1 cm distal, and 1 cm proximal axial ultrasonographic images (b) and schematic illustrations (c) of the superficial region of the IL from under the groin at a hip joint angle of 0°. Representative axial magnetic resonance images with recumbent posture on the right side of the examination bed with the right hip joint set at -10°, 0°, 30°, and 60° (d). The electrode location on the IL is surrounded by a circle. L1, a straight line drawn along the posterior end line of the ilium on both sides; L2 and L3, two lines drawn vertically to L1 at the medial and lateral edges of the IL (Jiroumaru et al. 2014). FA, femoral artery; IL, iliopsoas; RF, rectus femoris; SA, sartorius; TFL, tensor fasciae latae.
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Fig4: Confirmation of the electrode positions. (a) Electrode positions on the hip flexor muscles. Representative maximal perimeter IL, 1 cm distal, and 1 cm proximal axial ultrasonographic images (b) and schematic illustrations (c) of the superficial region of the IL from under the groin at a hip joint angle of 0°. Representative axial magnetic resonance images with recumbent posture on the right side of the examination bed with the right hip joint set at -10°, 0°, 30°, and 60° (d). The electrode location on the IL is surrounded by a circle. L1, a straight line drawn along the posterior end line of the ilium on both sides; L2 and L3, two lines drawn vertically to L1 at the medial and lateral edges of the IL (Jiroumaru et al. 2014). FA, femoral artery; IL, iliopsoas; RF, rectus femoris; SA, sartorius; TFL, tensor fasciae latae.

Mentions: The electrode for the RF was placed at the midpoint between the anterior inferior iliac spine (ASIS) and the superior border of the patella. The electrode for the SA was placed 8 cm distal from the ASIS along the line between the ASIS and the median of the tibial tuberosity parallel to the estimated muscle fibres. The electrode for the TFL was placed at the midpoint between the ASIS and the head of the greater trochanter. The electrode for the IL was placed at a level 3–5 cm distal from the ASIS (Jiroumaru et al. 2014), while the ultrasound probe was applied directly under the groin to identify the subcuticular existence of the IL. These electrodes were placed parallel to the longitudinal axis of the muscle (Figure 4). The reference electrode was attached on the right patella. Prior to attaching the electrodes, the skin was shaved, abraded, and cleaned with alcohol.Figure 4


Measurement of muscle length-related electromyography activity of the hip flexor muscles to determine individual muscle contributions to the hip flexion torque.

Jiroumaru T, Kurihara T, Isaka T - Springerplus (2014)

Confirmation of the electrode positions. (a) Electrode positions on the hip flexor muscles. Representative maximal perimeter IL, 1 cm distal, and 1 cm proximal axial ultrasonographic images (b) and schematic illustrations (c) of the superficial region of the IL from under the groin at a hip joint angle of 0°. Representative axial magnetic resonance images with recumbent posture on the right side of the examination bed with the right hip joint set at -10°, 0°, 30°, and 60° (d). The electrode location on the IL is surrounded by a circle. L1, a straight line drawn along the posterior end line of the ilium on both sides; L2 and L3, two lines drawn vertically to L1 at the medial and lateral edges of the IL (Jiroumaru et al. 2014). FA, femoral artery; IL, iliopsoas; RF, rectus femoris; SA, sartorius; TFL, tensor fasciae latae.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4221557&req=5

Fig4: Confirmation of the electrode positions. (a) Electrode positions on the hip flexor muscles. Representative maximal perimeter IL, 1 cm distal, and 1 cm proximal axial ultrasonographic images (b) and schematic illustrations (c) of the superficial region of the IL from under the groin at a hip joint angle of 0°. Representative axial magnetic resonance images with recumbent posture on the right side of the examination bed with the right hip joint set at -10°, 0°, 30°, and 60° (d). The electrode location on the IL is surrounded by a circle. L1, a straight line drawn along the posterior end line of the ilium on both sides; L2 and L3, two lines drawn vertically to L1 at the medial and lateral edges of the IL (Jiroumaru et al. 2014). FA, femoral artery; IL, iliopsoas; RF, rectus femoris; SA, sartorius; TFL, tensor fasciae latae.
Mentions: The electrode for the RF was placed at the midpoint between the anterior inferior iliac spine (ASIS) and the superior border of the patella. The electrode for the SA was placed 8 cm distal from the ASIS along the line between the ASIS and the median of the tibial tuberosity parallel to the estimated muscle fibres. The electrode for the TFL was placed at the midpoint between the ASIS and the head of the greater trochanter. The electrode for the IL was placed at a level 3–5 cm distal from the ASIS (Jiroumaru et al. 2014), while the ultrasound probe was applied directly under the groin to identify the subcuticular existence of the IL. These electrodes were placed parallel to the longitudinal axis of the muscle (Figure 4). The reference electrode was attached on the right patella. Prior to attaching the electrodes, the skin was shaved, abraded, and cleaned with alcohol.Figure 4

Bottom Line: The root mean square (RMS) value for the TFL at 30° (0.81 ± 0.19, p <0.005) and 60° (0.66 ± 0.17, p <0.001) and the SA at 60° (0.62 ± 0.24, p <0.005) were significantly decreased compared with those at 0°.However, the RMS value for the IL and RF did not change significantly.We conclude that, in a hip joint flexed position, the contribution of the IL to hip flexion movement is relatively larger than that of the other hip flexor muscles.

View Article: PubMed Central - PubMed

Affiliation: Graduate School of Sport and Health Science, Ritsumeikan University, 1-1-1 Noji Higashi, Kusatsu, Shiga, 525-8577 Japan ; Shiga School of Medical Technology, 967 Kitasaka-cho, Higashiomi, Shiga, 527-0145 Japan.

ABSTRACT
This study aimed to investigate muscle length-related electromyography (EMG) of the iliopsoas (IL) and other hip flexor muscles to determine individual muscle contributions to the hip flexion torque. Ten healthy sedentary young men participated in the EMG experiment. A subgroup of six subjects underwent a magnetic resonance imaging (MRI) measurement to confirm the region of the skin over the IL. Surface EMG signals were sampled from the IL, rectus femoris (RF), sartorius (SA), and tensor fasciae latae (TFL) using an active electrode. The subjects performed maximum voluntary isometric hip flexion with the right hip joint set at -10°, 0°, 30°, and 60°. The root mean square (RMS) value for the TFL at 30° (0.81 ± 0.19, p <0.005) and 60° (0.66 ± 0.17, p <0.001) and the SA at 60° (0.62 ± 0.24, p <0.005) were significantly decreased compared with those at 0°. However, the RMS value for the IL and RF did not change significantly. The RMS value and muscle length changes were significantly correlated in the IL (r =0.39, p <0.05), SA (r =0.51, p <0.001), and TFL (r =0.70, p <0.001), but not in the RF (r =0.22, p =0.180). We conclude that, in a hip joint flexed position, the contribution of the IL to hip flexion movement is relatively larger than that of the other hip flexor muscles.

No MeSH data available.