MCP Joints in Physiotherapy: Anatomy, Common Conditions, Assessment, and Interventions

What is MCP in Physiotherapy?

In physiotherapy, "MCP" refers to the Metacarpophalangeal Joints, which are the knuckles of the hand, connecting the metacarpal bones of the palm to the proximal phalanges of the fingers. These joints are crucial for the hand's dexterity, grip, and overall function, and are frequently a focus of assessment and intervention due to injury, inflammation, or degenerative conditions.

Understanding the MCP Joint: Anatomy and Function

The MCP joints are condyloid joints, allowing for movement in two planes: flexion/extension and abduction/adduction. There are five MCP joints in each hand, one for each finger (thumb to little finger).

• Anatomical Structure:
  • Bones: Each MCP joint is formed by the distal end of a metacarpal bone and the proximal end of a corresponding phalanx.
  • Articular Cartilage: The bone ends are covered with smooth articular cartilage, facilitating frictionless movement.
  • Joint Capsule: A fibrous capsule encloses the joint, providing stability and containing synovial fluid for lubrication and nourishment.
  • Ligaments: Key stabilizing ligaments include:
    • Collateral Ligaments: These are strong, cord-like structures on either side of the joint (radial and ulnar collateral ligaments) that prevent excessive sideways movement. They are taut in flexion, providing significant stability during gripping.
    • Palmar (Volmar) Plate: A thick, fibrocartilaginous structure on the palmar aspect of the joint, which strengthens the joint capsule and prevents hyperextension.
  • Tendons: Extensor tendons run over the dorsal aspect of the joint, and flexor tendons run through sheaths on the palmar aspect, enabling finger movement.
• Functional Significance: The MCP joints are fundamental to hand function, enabling:
  • Flexion and Extension: Bending and straightening the fingers at the knuckles, essential for grasping and releasing objects.
  • Abduction and Adduction: Spreading the fingers apart and bringing them together, crucial for fine motor control and object manipulation.
  • Grip Strength: The stability and mobility of the MCP joints are vital for effective power grip and precision grip.

Common Conditions Affecting the MCP Joints

Given their frequent use and exposure, MCP joints are susceptible to various conditions that often necessitate physiotherapy.

• Arthritis:
  • Osteoarthritis (OA): Degenerative "wear and tear" arthritis, common in older adults, leading to cartilage breakdown, pain, stiffness, and reduced range of motion.
  • Rheumatoid Arthritis (RA): A chronic autoimmune inflammatory disease that commonly affects the small joints of the hands, including the MCPs. It causes pain, swelling, stiffness, and can lead to joint deformity and functional loss.
• Sprains and Ligament Injuries: Often result from forceful hyperextension or sideways stress, leading to stretching or tearing of the collateral ligaments or palmar plate. Common in sports (e.g., "skier's thumb" – UCL injury of the thumb MCP).
• Tendonitis/Tenosynovitis: Inflammation of the tendons or their surrounding sheaths that cross the MCP joints. For example, extensor tendonitis can cause pain on the back of the hand.
• Fractures and Dislocations: Direct trauma can lead to fractures of the metacarpal heads or proximal phalangeal bases, or dislocation of the joint itself.
• Post-Surgical Rehabilitation: Following surgical interventions such as joint replacement (arthroplasty) or fusion (arthrodesis), physiotherapy is essential for recovery.

Assessment of MCP Joint Issues in Physiotherapy

A thorough physiotherapy assessment of the MCP joints involves both subjective and objective components to identify the cause of symptoms and guide treatment.

• Subjective History:
  • Pain Characteristics: Location, intensity, type (sharp, dull, aching), aggravating and easing factors.
  • Mechanism of Injury: If applicable, how the injury occurred.
  • Functional Limitations: Impact on daily activities, work, hobbies, and sports.
  • Medical History: Relevant systemic conditions (e.g., RA, diabetes), previous injuries, or surgeries.
• Objective Examination:
  • Observation: Visual inspection for swelling, redness, deformity, muscle wasting, or skin changes.
  • Palpation: Gently feeling the joint and surrounding structures to locate tenderness, swelling, or crepitus (grating sensation).
  • Range of Motion (ROM): Assessing active and passive flexion, extension, abduction, and adduction, and noting any limitations or pain.
  • Special Tests: Specific maneuvers to stress particular ligaments or tendons to identify instability or injury (e.g., collateral ligament stress tests).
  • Strength Testing: Assessing grip strength and individual finger strength.
  • Neurovascular Assessment: Checking sensation and circulation in the hand and fingers if nerve involvement is suspected.
  • Functional Tasks: Observing the patient performing tasks like grasping objects, writing, or typing.

Physiotherapy Interventions for MCP Joint Conditions

Physiotherapy aims to reduce pain, restore range of motion, improve strength, and enhance functional independence. The approach is tailored to the specific condition and individual needs.

• Pain and Swelling Management:
  • Rest and Activity Modification: Advising on avoiding aggravating activities.
  • Cryotherapy (Ice): To reduce inflammation and pain.
  • Therapeutic Modalities: Such as ultrasound or transcutaneous electrical nerve stimulation (TENS) may be used for pain relief.
• Manual Therapy:
  • Joint Mobilization: Gentle, controlled movements applied by the therapist to improve joint play and range of motion, particularly effective for stiffness.
  • Soft Tissue Mobilization: Techniques to address muscle tightness or fascial restrictions in the hand and forearm that may contribute to MCP pain.
• Therapeutic Exercise:
  • Range of Motion Exercises: Gentle active and passive exercises to maintain or restore joint mobility.
  • Strengthening Exercises: Progressive resistive exercises for the intrinsic muscles of the hand and forearm muscles to improve grip strength and stability around the MCP joints. Examples include squeezing soft balls, using resistance bands, or finger presses.
  • Dexterity and Fine Motor Coordination: Exercises involving small object manipulation (e.g., picking up coins, buttoning) to improve precision and functional skills.
  • Stretching: For tight muscles or ligaments affecting the hand.
• Splinting and Orthotics: Custom or prefabricated splints may be used to:
  • Immobilize the joint to promote healing after injury or surgery.
  • Protect the joint from stress.
  • Provide support and reduce pain, especially in inflammatory conditions like RA.
  • Correct deformities.
• Patient Education and Self-Management:
  • Joint Protection Strategies: Teaching techniques to minimize stress on the MCP joints during daily activities.
  • Ergonomic Advice: Modifying workspaces or tools to reduce strain.
  • Home Exercise Program: Instruction on exercises to perform independently.
  • Pain Management Techniques: Education on pacing activities and other self-care strategies.

Rehabilitation Principles and Prognosis

Rehabilitation for MCP joint conditions follows a progressive approach, aiming for a safe and effective return to function.

• Progressive Loading: Exercises are gradually advanced in intensity and complexity as the joint heals and strength improves.
• Functional Integration: Treatment progresses from isolated joint movements to incorporating the hand into complex, multi-joint functional tasks relevant to the individual's daily life, work, and hobbies.
• Long-Term Management: For chronic conditions like arthritis, physiotherapy emphasizes ongoing joint protection, pain management, and a consistent exercise regimen to maintain function and prevent further deterioration.
• Prognosis: The outlook for MCP joint conditions varies widely depending on the specific diagnosis, severity, individual adherence to treatment, and presence of systemic diseases. Early intervention generally leads to better outcomes.

When to Seek Physiotherapy for MCP Joint Pain

It is advisable to consult a physiotherapist if you experience:

• Persistent pain or stiffness in your knuckles.
• Swelling, redness, or warmth around the MCP joints.
• Difficulty with hand movements, grip, or fine motor tasks.
• Pain that worsens with activity or interferes with daily life.
• Symptoms following an acute injury or trauma to the hand.

A physiotherapist can accurately diagnose the problem and develop a personalized treatment plan to restore hand function and improve quality of life.