GENERAL INFORMATION
The longissimus is the most significant part of the erector spinal muscle group, which is critical for spinal movement, such as extension, lateral flexion, spine rotation, and maintaining proper posture. Additionally, the longissimus itself is subdivided into three parts based on their locations: longissimus capitis, longissimus cervicis, and longissimus thoracis.
ORIGIN
Firstly, the longissimus thoracis originates from the transverse processes of the lumbar vertebrae and the posterior part of the iliac crest, the upper thoracic vertebrae, and the lumbodorsal fascia. Next, the longissimus cervicis and capitis originate from the transverse processes of the lower cervical vertebrae, upper thoracic vertebrae, and the lumbodorsal fascia. Lastly, the longissimus lumborum originates from the transverse processes of the lumbar vertebrae and the lumbodorsal fascia.
INSERTION POINT
Specifically, the longissimus thoracis inserts on the transverse process of all thoracic vertebrae, the lower nine or ten ribs, and the cervical vertebrae C2-C6. Additionally, the longissimus cervicis inserts on the transverse processes of the cervical vertebrae C2-C6. Meanwhile, the longissimus lumborum inserts on the transverse process of the last thoracic vertebrae T12 and the ribs. Furthermore, the longissimus capitis inserts into the mastoid process of the temporal bone.
MAJOR ARTERIES
Moreover, these muscles are primarily supplied by the lateral sacral arteries, deep cervical arteries, and posterior intercostal arteries.
NEURAL INNERVATION
Also, these muscles are innervated by the dorsal rami of the spinal nerves.
TRIGGER POINT
Trigger points for the longissimus are generally found within the muscle belly along the spine. Manual pressure or massage can target these points for tension relief. Furthermore, a trigger point in the longissimus can cause pain and tightness in the lower back and upper thigh.
CONCENTRIC FUNCTION
Importantly, these muscles play a crucial role in extending, rotating, and laterally flexing the vertebral column and maintaining proper posture. The longissimus capitis also helps in turning the head to the same side.
ECCENTRIC FUNCTION
These muscles control the speed and direction during flexion of the vertebral column, such as when bending forward or to the side. The longissimus works eccentrically, controlling the movement of the spine during activities such as deadlifts and good mornings.
ISOMETRIC FUNCTION
Similarly, the longissimus works isometrically to maintain proper posture while sitting or standing. When maintaining an upright posture or carrying a heavy load, these muscles work isometrically to stabilise the spine.
RELATED MUSCLES (SCIENTIFIC NAMES)
- Iliocostalis: Part of the erector spinae group, it helps extend and laterally flex the vertebral column.
- Transversospinalis: This group of muscles assists in stabilising and rotating the vertebral column.
- Spinalis: Located nearest to the spine, it helps extend and laterally flex the vertebral column.
- Multifidus: Provides stability to the vertebrae during movement, located along the spine.
- Quadratus Lumborum: Helps with lateral flexion and extension of the lumbar spine.
- Latissimus Dorsi: A large muscle in the back that extends, adducts, and medially rotates the arm.
ANTAGONIST MUSCLES
- Rectus Abdominis: Flexes the spine and stabilises the core.
- Transversus Abdominis: Compresses abdominal contents and stabilises the trunk.
- Obliques (Internal and External): Rotate and laterally flex the spine, and stabilise the trunk.
- Psoas Major: Assists in trunk flexion and stabilisation, a deep hip flexor.
COMMON INJURIES
- Strains: Due to improper lifting techniques or overuse, causing muscle fibre damage and pain.
- Sprains: Involve ligament damage from sudden movements or excessive strain.
- Muscle spasms: Sudden, involuntary contractions often due to fatigue, overuse, or improper posture.
- Lower back pain: Often due to overuse, poor posture, or injury, impacting the longissimus muscles.
- Sciatica: Compression or irritation of the sciatic nerve causing pain that can affect these muscles.
EXERCISES
- Back extensions: Perform on a stability ball or Roman chair to strengthen the erector spinae muscles.
- Deadlifts: Use proper form to engage the longissimus and other back muscles, improving strength and stability.
- Superman training: Lie face down and lift arms and legs off the ground simultaneously to strengthen the lower back.
- Prone back extensions: Lie face down and lift your chest off the ground to target the lower back muscles.
- Good mornings: Bend at the hips with a straight back to target the lower back and hamstrings.
STRETCHES
- Child’s pose stretch: Sit back on your heels with arms extended forward, stretching the back muscles.
- Cat-Camel stretch: Alternate between arching and rounding your back to improve flexibility and reduce tension.
- Lumbar rotation stretch: Lie on your back with knees bent and rotate them to each side to stretch the lower back.
- Standing or seated forward bends: Bend forward at the hips to stretch the back and hamstrings.
- Seated spinal stretch: Sit with one leg extended and the other bent, twisting the torso to stretch the spine.