Often, the definitive cause of mechanical back pain cannot be reliably identified. However, several factors and mechanisms are commonly implicated:-

• Muscle Strains and Ligament Sprains: This is one of the most frequent causes.
  • Sudden awkward movements: Twisting, bending, or lifting improperly can overstretch or tear muscles (strain) or ligaments (sprain) in the back.
  • Repetitive micro-trauma: Repeated stresses from poor posture, prolonged sitting or standing, or repetitive bending/lifting can gradually lead to micro-tears and inflammation.
• Disc Problems
  • Disc Degeneration (Degenerative Disc Disease): As we age, the intervertebral discs (cushions between vertebrae) can lose water content, become less flexible, and develop small cracks. This can lead to discogenic pain.
  • Disc Bulge/Protrusion: The soft inner nucleus of the disc can bulge outward, potentially irritating nearby nerves.
  • Disc Herniation (Ruptured Disc): In more severe cases, the disc material can fully protrude or rupture, directly compressing a nerve root, leading to sciatica (pain radiating down the leg).
• Facet Joint Dysfunction: The facet joints are small joints at the back of each vertebra that allow for spinal movement. If these joints become inflamed, stiff, or undergo degenerative changes (osteoarthritis), they can cause localized back pain.
• Sacroiliac (SI) Joint Dysfunction: The SI joints connect the base of the spine (sacrum) to the pelvis. Dysfunction or inflammation in these joints can cause pain in the lower back, buttocks, and sometimes the leg.
• Postural Issues:
  • Prolonged Static Postures: Sitting or standing for extended periods, especially with poor ergonomics, can put sustained stress on spinal structures.
  • Poor Lifting Mechanics: Using your back instead of your legs when lifting heavy objects significantly increases the risk of injury.
• Lack of Physical Activity/Weak Core Muscles: Weak abdominal and back muscles (core muscles) provide less support for the spine, making it more vulnerable to strain and injury.
• Overweight/Obesity: Excess body weight puts additional stress on the spine, particularly the lower back.
• Sudden Movements: Sneezing, coughing, or sudden twists can sometimes trigger a painful episode.
• Stress and Psychosocial Factors: While not a direct mechanical cause, stress, anxiety, and depression can influence pain perception and muscle tension, contributing to chronic mechanical back pain.

Symptoms of Mechanical Back Pain

• Localized Pain: Most commonly felt in the lower back, but can occur in the mid or upper back.
• Pain that Varies with Activity:
  • Often worsens with certain movements (e.g., bending forward, lifting, twisting, prolonged sitting or standing).
  • May improve with rest or specific positions (e.g., lying down, specific stretching).
  • Pain might be worse in the morning and ease as you move, or it might worsen throughout the day.
• Stiffness: Especially noticeable after periods of inactivity, like waking up in the morning or after sitting for a long time.
• Muscle Spasm: The muscles around the painful area may go into spasm, feeling tight and tender.
• Tenderness to Touch: The affected area of the spine or surrounding muscles may be sore when pressed.
• Referred Pain: Pain may radiate to the buttocks or thighs, but typically does not go below the knee (if it does, especially with numbness, tingling, or weakness, it could indicate nerve root compression like sciatica, which can be a component of mechanical back pain, but requires further assessment).