Back pain is a common issue affecting many individuals, often limiting daily activities and reducing overall quality of life. The spine, a complex structure of bones, discs, and muscles, relies on various components for its stability and movement. Among these, the multifidus muscle plays a significant role in maintaining spinal health.
Understanding the Multifidus Muscle
The multifidus muscle is a deep layer of muscle located along both sides of the spinal column, extending from the sacrum at the base of the spine up to the cervical spine in the neck. It is comprised of numerous short, fleshy and tendinous fasciculi that fill the grooves on either side of the vertebral spinous processes. These fasciculi vary in length, with some connecting adjacent vertebrae and others spanning up to three to five vertebral segments.
The multifidus muscle plays a significant role in stabilizing the vertebral column and controlling segmental movement. It works to provide stiffness and stability at each spinal joint. When contracting bilaterally, these muscles extend the spine, and when contracting unilaterally, they assist in lateral flexion to the same side and rotation to the opposite side. It also contributes to maintaining proper posture.
Recognizing Multifidus Pain
Multifidus pain has specific characteristics. It is described as a deep, localized ache or dull discomfort, felt directly over the affected spinal segment. The pain may also manifest as sharp sensations during certain movements.
Individuals experiencing multifidus pain report increased discomfort with simple movements like bending, twisting, or prolonged periods of sitting or standing. This muscle dysfunction can lead to weakness or stiffness in the lower back and a limited range of motion. While the pain is localized, it can sometimes radiate into the buttocks or upper legs, but it does not extend below the knee or elbow.
Causes and Risk Factors
Multifidus pain can develop from a variety of factors. Sudden movements, such as lifting heavy objects incorrectly or engaging in strenuous sports activities, can lead to muscle strain or sprain in the multifidus. This trauma can damage the muscle.
Chronic issues like poor posture, repetitive strain, and muscle imbalances also contribute to multifidus dysfunction. For instance, slouching or hunching over can weaken the multifidus muscles over time, leading to pain. A sedentary lifestyle and lack of regular physical activity can also decondition the muscle, making it more susceptible to pain. Other contributing factors include core muscle weakness, as the multifidus is part of the core group that stabilizes the spine, and degenerative conditions like arthritis or disc degeneration, which can affect muscle stability. Previous spinal surgery may also alter movement patterns, placing additional stress on the multifidus.
Diagnosis and Treatment Approaches
Diagnosing multifidus pain begins with a thorough physical examination. A healthcare professional will assess a patient’s medical history, perform palpation to locate tender spots along the spine, and conduct movement tests to identify limitations and pain triggers.
Imaging studies like X-rays or MRI scans may be used to rule out other spinal conditions such as severe degenerative disc changes, advanced osteophytosis, or herniated discs, which can also contribute to back pain. While MRI does not always identify the precise source of low back pain, it is useful for detecting signs of atrophy and degenerative changes, such as fatty infiltration within the multifidus muscle, which are correlated with functional impairment and pain. For instance, fatty degeneration often appears as hyperintense fatty tissue on axial T1 and T2-weighted MRI images, replacing normal muscle tissue.
Treatment approaches for multifidus pain often involve a combination of strategies. Physical therapy is a common non-invasive approach, focusing on specific exercises to strengthen and stabilize the multifidus and surrounding core muscles. These exercises aim to improve muscle activation, endurance, and overall spinal stability. Manual therapy techniques, such as soft tissue mobilization and joint mobilization, may also be used by physical therapists to reduce muscle stiffness, improve flexibility, and alleviate pain.
Medications can provide symptomatic relief. Over-the-counter pain relievers and anti-inflammatory drugs may help manage pain and reduce inflammation. In some cases, muscle relaxants might be prescribed to address muscle spasms. Lifestyle modifications are also encouraged, including adopting proper ergonomics at work and home, maintaining a healthy weight, and avoiding prolonged static postures to reduce strain on the multifidus muscle. In more advanced cases, interventions like nerve stimulation or injections may be considered, but these are generally pursued after conservative treatments have been explored.