LUMBAR SPINE ANATOMY

Physiotherapy services in Edmonton for Lower Back

Excelsior Physiotherapy welcomes you all to the online patient resource on lumbar spine issues.

It is essential to learn about the major parts related to your lower back and the way these parts function to take care of your back issues.

Anterior referring to your spine’s front side and posterior referring to the back side of your spine are mostly used anatomic terms when speaking about lower back pain. This spine’s section, which form the lower back is referred to as lumbar spine. The front side of the lumbar spine is known as anterior lumbar area and the back side of the lower spine is referred to as posterior lumbar area.

With this article, you will get a clear idea about the overall anatomy of your lower back. It will help you learn:

• What are major parts constituting your lower back
• The way these low back parts function

SIGNIFICANT STRUCTURES

The significant parts of your lumbar spine are:

• Joints and bones
• Spinal segments
• Nerves
• Muscles
• Connective tissues

This section throws light on the significant structures in every category.

Joints and Bones

Our whole body is built with 24 bones of your spine, which is also known as vertebrae. Forming a stacked up look, the vertebrae leads to the formation of your spinal column. The upright position and support of your body is offered by the spinal column. Along the side of your spine, you can find three distinct curves. The cervical spine with a slight inward curve, forms your neck. The thoracic spine also called your mid back flaunts a curve facing outward. Kyphosis refers to the external curve of thoracic spine. Your lumbar spine or lower back also has a slight curve facing inward known as lordosis.

Spine and Its Three Curves

The lumbar spine consists of five vertebrae at your lower back. Physicians call these five vertebrae as L1, L2…L5. L5 refers to your lower most vertebrae present in your lumbar spine and acts as a connection to a triangle-shaped bone called sacrum lying at your spine’s base sandwiched in between the pelvic bones. Some might even have a sixth vertebrae in their lumbar spine. However, this additional vertebra will not cause any specific issues in lower back.

Lower Vertebrae

Vertebral body refers to a circular bone block of a vertebra. When compared to the other parts in your spine, these vertebrae are stouter and lengthier. It is due to the reason that your lower back is efficient enough to resist pressure caused by weight gain and when performing activities like walking, lifting, and carrying. Plus, power packed and huge muscles are also found close to the lumbar spine putting more pressure on the vertebral bodies of the lumbar spine.

Every vertebra has a circular bone attached to it. This bone ring consists of two parts, such as dual pedicle bones connecting with the vertebra’s back and dual lamina bones connecting pedicles to form a ring shape. These lamina bones create a n exterior ring encapsuling the bony ring. The stacking of vertebrae one over the other leads to a hollow formation covering the nerves and the spine. It also acts as a shield for nervous tissues.

• Bony Ring: Spinous processes are projections that can be found at the meeting point of the lamina bones on the spine’s back. It can be felt when you touch along the spine. The bony knobs of the vertebra are called transverse process.
• Facet Joints: Facet joints location lies in the middle of the vertebrae segment of the spine’s back. These joints comprise of tiny bone knobs lining along the spine to form a link connecting the vertebrae to each other. The face joints are aligned to help you perform activities like bending back and fro freely.
• Articular Cartilage: The facet joints upper part is wrapped with articular cartilage, which is a rubbery, and soft to cushion major joints. This cartilage helps your bone to support movement without any friction.
• Neural Foramen: Neural foramen refers to a tiny tunnel found ta either side of the vertebra. It is also called foramina to refer it in plural form. The dual nerves exiting your spine along the vertebrae will pass through the foramina on either side. The opening will have intervertebral disc resting atop it. When your disc is bulged or herniated, it might press the nerves. The foramen’s back side has a facet joint, which has bone spurs in the tunnel, cause nerve pain and narrows the tunnel.

Nerves

The construction of bone rings to form a hollow tunnel covering the spinal column around your spinal cord. Thousands of nerve fibers constitute together to make spinal cord look like a lengthy wire. These bony rings protect your spine from all kinds of damages.

Spinal Cord

The spinal cord proceeds to touch the L2 vertebra and beneath it, the spinal canal surrounds the nerve bundle running along your pelvic organs and lower limbs. It is referred to as cauda equina in Latina denoting a horse’s tail. Two big nerves found between the vertebrae detach from the spinal cord on either side. Such spinal nerves group together form the major nerves, which pass through your legs, lower back, and pelvic organs.

Connective Tissues

The cells present in your body create fiber networks called connective tissues. Ligaments refer to sturdy connective tissues attaching the bones with the other. Many lengthy ligaments connect your vertebrae’s back and front portions. On the front of the vertebrae, you can find anterior longitudinal ligament running along the length. Along with it, other two ligaments, such as ligamentum flavum and posterior longitudinal ligament also run through the front and back side of the vertebral bodies. Some thick ligaments also connect the lumbar spine and the sacrum beneath your pelvic region and L5.

Ligaments

Intervertebral disc constituted by connective tissues is a unique structure. The disc fibers are constructed by a special type of cells known as collagen cells. These fibers are similar to rope strands of nylon or like a net with crisscross pattern.

Intervertebral Disc and Its Parts

Your intervertebral disc comprises of two parts, namely the nucleus, the spongy center and annulus, sturdy ligament rings around the nucleus.

Muscles

Low Back Muscles

The arrangement of the muscles on your lower back are in layers. The superficial layer of the skin is surrounded by fascia with thick tissue cells. The mid layer is known as the erector spinae featuring strap-like muscles running above and below the low back, chest, and lower ribs. They connect with the lumbar spine forming sturdy tendon biding the bones present on the sacrum, pelvis, and lower back. The deep layered muscles attach to the bones of your spine and keeps y0our spine erect when performing activities by coordinating muscular actions.

Segments of the Spine

A perfect way to gain an insight about the lumbar spine anatomy is by taking a glance at its spinal segment. Every spine segment will have two vertebrae divided through an intervertebral disc, each section having a facet joint and spinal column.

Spinal Segment

An intervertebral disc divides the vertebra into two in a spinal segment. This disc performs like a shock absorber and protects your spine from gravity pull. It also prevents damage to spine when performing heavy activities that might put stress on the spine like lifting weight, running and jumping. The two facet joints connecting it move as a team in the lumbar spine, it help you bend and turn your back effortlessly.

SUMMARY

Several significant body parts and bone form low back anatomy. Having a better understanding about the structures and region of your lumbar spine will help you keep an eye on your overall health and handle it efficiently when faced with a low back issue.