Introduction[edit | edit source]
- Is in the shape of a fan located in the posterior pelvis, on both sides and connects the sacrum to the iliac tuberosities.
- Is composed mainly of collagen fibres, it is strong enough to support the sacrum and prevent adverse changes under body weight
Anatomy[edit | edit source]
The STL has a broad fan-like origin from the sacrum, coccyx, ilium and sacroiliac joint capsule. Its fibres converge to course caudally to insert into the medial ischial tuberosity and additional fibres (known as the falciform ligament) extend to the ischial ramus .
It forms a boundary of the greater and lesser sciatic foramen. Many of its fibres blend with other musculotendinous structures:
- Provides extensive insertion for the gluteus maximus muscle
- Distal fibres partially blend with the proximal tendon of the long head of biceps femoris
- Sacrospinous ligament
- Dorsal sacroiliac ligament
The sacrotuberous ligament is pierced by coccygeal branches of the inferior gluteal artery, the perforating cutaneous nerve, and branches of the coccygeal plexus.
Function[edit | edit source]
- Sacrotuberous ligament STL assists in pelvic stability, the obliquity arrangement of STL on both sides prevent the anterior tipping of sacrum by acting to control sacral nutation.
- STL prevents the sacrum from tipping forward when downward pressure is applied to the spine. It is stressed with sports that create a lot of arching in the lower back like high jumping, golfing, gymnastics, pitching and volleyball spiking.
- Connecting the lower limb with the trunk, biceps femoris, and perineum to the thoracolumbar fascia, and erector spinae.
- STL and sacrospinous ligament stabilize the sacrum against twisting with the pelvis, and excessive side bending. Hence, an imbalance between STL on both sides cause pelvic rotation, SIJ strain, or LBP.
Clinical relevance[edit | edit source]
- May be secondary to sacrotuberous ligament calcification
- Normally the sacrotuberous ligament is thin and can not be palpated externally. However, when the ligament is stressed, usually with aggressive physical activity or injury, it can become thick and tight. This can also cause the ligament ossification and pressure on the pudendal nerve.
- When the ligament becomes tighter than normal its pain pattern is referred down to the central aspect of the back of the thigh and in severe injuries or pain, it may go down to the calf and into the heal. That interferes with hamstring referred pain pattern, if the referred pain is at the posterior thigh only.
- Note: A 2016 A systematic review of the morphology and function of the sacrotuberous ligament reported "The sacrotuberous ligament (STL) has been linked to conditions such as pelvic girdle pain and pudendal nerve entrapment, yet its contribution to pelvic stability is debated... Functionally, the STL may limit sacral nutation but it appears to have a limited contribution to pelvic stability."
Phyiotherapy[edit | edit source]
Initial physical therapy goals are to reduce pain by minimizing irritation of an injury and reducing local spasm and inflammation. For a sacrotuberus ligament sprain techniques include:
- Appropriate rest eg stopping sports activities that produce discomfort
- Ice for pain relief (ice several times per day for up to 20 minutes per session).
- Exercises to increase strength and stability in the area of the lower back and sacrum help prevent injury to the sacrotuberous ligaments. Core strengthening exercises combined with stretches to increase flexibility in the hamstrings, hip flexors and gluteal muscles will improve shock absorption in the lower extremity and reduce stress on the ligaments.
Assessment[edit | edit source]
- Stand beside the patient, one hand reaches across to the opposite ischial tuberosity, the other to the coccyx, between both the sacrotuberous ligament runs. It is anterior to the medial margin of glut maximus, lateral to the upper gluteal cleft not on the muscle itself.
- Press into the ligament, you will feel roby / hard sensation underneath your fingers.
- Compare both sides and stay longer on the side you feel that is more restrict or less bony space. During the assessment, the client may experience numbness or perineal pain at the mid part of the ligament where the pudendal nerve gets entraped.
Treatment[edit | edit source]
The treatment procedure as the assessment technique with applying firm, gentle, and mild resistance on the ligament avoid gliding or friction movement until you feel the tissue release underneath your finger.
References[edit | edit source]
- Radiopedia Sacrotuberous lig. Available: https://radiopaedia.org/articles/sacrotuberous-ligament (accessed 1.9.2021)
- Radiopedia Sacrotuberous ligament ossification Available:https://radiopaedia.org/cases/sacrotuberous-ligament-ossification (accessed 1.9.2021)
- Livestrong STL Available:https://www.livestrong.com/article/476575-physical-therapy-for-sacrotuberous-ligament-pains/ ( accessed 1.9.2021)
- PAINLess. Sarotuberous Ligament Anatomy. Available from: http://www.youtube.com/watch?v=Y6pKbnetuZU[last accessed 22/7/2020]
- Aldabe D, Hammer N, Flack NA, Woodley SJ. A systematic review of the morphology and function of the sacrotuberous ligament. Clinical Anatomy. 2019 Apr;32(3):396-407.https://pubmed.ncbi.nlm.nih.gov/30592090/ (accessed 1.9.2021)
- AdvancedTrainings. Sacrotuberous Ligament - Advanced Myofascial Techniques DVD Series. Available from: http://www.youtube.com/watch?v=bj_z5zgNA3I[last accessed 22/7/2020]