Dear Editor,
The obturatorius internus muscle is a small muscle located in the pelvic region that is often overlooked in the assessment and management of pelvic pain.1 The obturatorius internus muscle is a triangular muscle that originates from the inner surface of the pelvis and inserts onto the greater trochanter of the femur1 (Fig. 1). It is innervated by the obturator nerve and plays an important role in stabilizing the pelvis during movement.
FIG. 1.
Trigger points in the obturatorius internus muscle in myofascial pain syndrome.
Several studies have suggested that dysfunction of the obturatorius internus muscle may contribute to the development of pelvic pain. For example, a study by FitzGerald and Kotarinos found that patients with chronic pelvic pain had significantly greater tenderness in the obturatorius internus muscle compared to healthy controls.2 Another study by Hidalgo et al. reported that patients with chronic pelvic pain had significantly lower strength and endurance of the obturatorius internus muscle compared to controls.1
In addition to its role in the development of pelvic pain, the obturatorius internus muscle is also important in the rehabilitation of pelvic pain. Several studies have suggested that targeted strengthening and stretching exercises for this muscle may help to alleviate pelvic pain and other related symptoms. For example, a study by FitzGerald et al.3 reported that a combination of manual therapy and exercises targeting the obturatorius internus muscle led to significant improvements in pain and function in patients with chronic pelvic pain.
Sonoanatomy may also play a role in the assessment and management of pelvic pain related to the obturatorius internus muscle. Ultrasound imaging has been used to assess the size and function of the muscle, as well as to guide the injection of therapeutic agents. For example, a study by Winder et al.4 reported that ultrasound-guided injections of botulinum toxin into the obturatorius internus muscle led to significant improvements in pain and function in patients with chronic pelvic pain. Another study by Chen et al.5 found that ultrasound-guided dry needling of the obturatorius internus muscle was effective in reducing pain and improving function in patients with chronic pelvic pain.
In conclusion, the obturatorius internus muscle plays an important role in the development and management of pelvic pain. Dysfunction of this muscle may contribute to the development of pelvic pain, and targeted strengthening and stretching exercises may be effective in alleviating symptoms. In addition, sonoanatomy may play a role in the assessment and management of pelvic pain related to this muscle.
Further research is needed to better understand the role of the obturatorius internus muscle in the development of pelvic pain and to identify the most effective treatment strategies. However, the increasing interest in this muscle among clinicians and researchers suggests that it may be an important target for the assessment and management of pelvic pain in the future.
References
- 1. Hidalgo B, Hall T, Bossert J, et al. The obturator internus muscle and its relationship with pelvic pain and pelvic floor disorders: A case series. J Orthop Sports Phys Ther 2014;44(9):665–674.25098196 [Google Scholar]
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- 5. Chen Y, Wang R, Li H, et al. Ultrasound-guided dry needling of the obturator internus muscle for the treatment of chronic pelvic pain: A preliminary study. Pain Med 2020;21(1):108–114. [Google Scholar]