Myofascial Force Transmission Between Latissimus Dorsi and Gluteus Maximus

A study from Brazil investigated whether regular running influences myofascial force transmission (MFT) between the latissimus dorsi (LD), thoracolumbar fascia, and contralateral gluteus maximus (GM), a pathway connecting the shoulder, trunk, and hip. The hypothesis was that runners, due to potential increases in tissue stiffness from regular sports practice, would exhibit greater MFT and altered passive properties in the lumbar and hip regions during LD contraction compared to sedentary individuals.

Fifty-four individuals were included, divided into runners (regular running practice) and sedentary individuals. , the study highlighted the influence of regular physical activity on lumbar stiffness and hip properties during latissiums dorsi contraction.  The study found:

1. Lumbar Stiffness:
   • Contraction of the latissimus dorsi significantly increased lumbar stiffness in both runners and sedentary individuals.
   • Runners demonstrated a greater increase in lumbar stiffness during latissimus dorsi contraction compared to sedentary individuals. This suggests that regular running may enhance the ability of the latissimus dorsi to transmit force to the lumbar region.
2. Hip Properties:
   • Latissimus dorsi contraction caused the hip to shift toward greater external rotation and increased passive hip torque and stiffness in both groups.
   • However, there were no significant differences between runners and sedentary individuals in these hip properties, indicating that the myofascial force transmission effects at the hip were similar in both groups.
3. Force Transmission:
   • The observed changes in lumbar stiffness and hip properties during latissimus dorsi contraction suggest that force is transmitted from the shoulder to the lumbar and hip regions, even when the trunk and hip muscles are relaxed.
   • Runners’ greater lumbar stiffness may result from adaptations to regular physical activity, such as increased force generation by the latissimus dorsi, rather than higher muscle activation levels.

Implications for Therapists

Implications:

The findings provide in vivo evidence of myofascial transmission between the Latissimus Dorsi and contralateral Gluterus Maximus, supporting the concept of a body-wide fascial network.

Regular running may enhance lumbar stiffness during Latissimus dorsi contraction, but this does not translate to greater force transmission at the hip joint.

The study highlights the importance of tissue stiffness and force transmission in understanding movement and stability, particularly in athletes. Therapists should account for these adaptations when designing rehabilitation or training programs.

Tissue stiffness plays a critical role in myofascial force transmission. Therapists can incorporate techniques to modulate tissue stiffness, such as manual therapy or targeted exercises, to optimize movement and reduce injury risk.