Effective Physiotherapy Techniques for Knee Osteoarthritis Relief

Knee osteoarthritis (KOA) is a degenerative and chronic disease that involves the whole joint, not just articular cartilage, affecting subchondral bone, capsule, ligaments, synovial membrane and muscles. Knee OA is a major cause of morbidity and functional limitation, particularly in elderly patients. It is linked to disabilities caused by pain, quadriceps weakness, and reduced proprioception.

  

Mechanical and Biological Factors Involved in Knee Osteoarthritis

1. Higher shear forces during gait contribute to cartilage degeneration.
2. Obesity and metabolic syndrome accelerate OA progression.
3. Blood vessel and nerve invasion into articular cartilage and osteophytes worsens KOA.
4. Estrogen accelerates cartilage degradation via estrogen receptors.
5. Inflammation is a key driver of KOA progression, along with aging, metabolic disorders, hormonal changes and mechanical stress.

 

Signs and Symptoms of Knee Osteoarthritis

• Swelling around the knee joint due to inflammation.
• Crepitus is felt during knee flexion and extension movement.
• Muscles around the knee may weaken over time which increases the risk of falls and functional limitations.
• Intermittent pain that worsens with weight-bearing and during night but improves with rest.
• Neuropathic pain and central sensitization can develop in severe cases.
• Stiffness is common, especially in the morning, lasting less than 30 minutes.
• Early-stage KOA affects end-range motion, in advanced stages, overall motion is reduced.

 

Diagnosing Knee Osteoarthritis

As a physiotherapist, diagnosing knee osteoarthritis involves a combination of patient history, physical examination, and functional assessment. Here’s a step-by-step approach:

Patient History

Ask about pain (location, intensity, and aggravating activities), stiffness and difficulty with movements like walking, standing or climbing stairs.

Physical Examination

Inspection:

• Look for swelling, joint deformity or muscle wasting around the knee.
• Check for gait abnormalities, such as limping or altered walking patterns.
• Look for crepitus.

Palpation:

• Gently palpate the joint line and surrounding areas for tenderness.
• Check for fluid buildup in the knee joint.

Range of Motion (ROM):

• Assess both active and passive ROM of the knee (flexion and extension). Limited movement may indicate OA.

Functional Tests

• Squat Test: Ask the patient to squat. Difficulty or pain during this movement often indicates OA.
• Step Test: Ascending and descending stairs may elicit pain in OA patients.
• Single-leg stance: Test the patient’s ability to balance on one leg to assess stability and muscle strength.

Special Tests

• Patellar Grind Test: Apply gentle pressure on the patella and ask the patient to contract the quadriceps. Pain or grinding suggests cartilage damage.
• Joint Line Tenderness: Palpating along the joint line while flexing and extending the knee may reveal tenderness specific to OA.

Outcome Measures

Use standardized questionnaires like the WOMAC (Western Ontario and McMaster Universities Arthritis Index) to assess pain, stiffness, and functional limitations.

Imaging Studies

Physiotherapists can suggest X-rays if needed. Common X-ray findings in knee OA include:

• Joint space narrowing.
• Osteophytes (bone spurs).
• Subchondral sclerosis (hardening of the bone beneath the cartilage).
• Bone deformities or changes in alignment.

 

Differential Diagnosis

• Rheumatoid Arthritis
• Gout
• Pseudogout (calcium pyrophosphate dihydrate crystal deposition disease)
• Osteonecrosis (avascular necrosis)
• Meniscal Tears
• Hoffa's Fat Pad Syndrome
• Ligament injuries (e.g., ACL, PCL)
• Patellofemoral Pain Syndrome
• Bursitis (e.g., prepatellar bursitis)
• Tendinopathy (e.g., quadriceps tendinopathy)
• Infections (e.g., septic arthritis)
• Fractures (e.g., stress fractures)
• Bone Tumors (e.g., osteosarcoma)
• Chondromalacia Patellae

 

Physiotherapy Management of knee Osteoarthritis

Patient Education

• Educate the patient about the nature of knee OA, how joint degeneration occurs, and the importance of managing symptoms.
• Stress the importance of losing weight if necessary, as even small reductions in weight can significantly reduce knee joint load and pain.
• Teach the patient how to adjust their activities to reduce stress on the knee. Encourage low-impact activities and advise against excessive squatting, kneeling, or high-impact sports.

 

Pain Management

Electrical stimulation (ES) has shown promise for addressing muscle weakness and alleviating symptoms of knee osteoarthritis, modalities includes:

Transcutaneous Electrical Nerve Stimulation (TENS)

Commonly used TENS parameter are frequency of 50-75 Hz, pulse duration of 200-400 microseconds and treatment time of 20 minutes. Combining TENS with exercise enhances long-term pain relief and function

Therapeutic Ultrasound

It works by converting electrical energy into heat, promoting muscle relaxation, tissue regeneration, and reducing inflammation. Pro-inflammatory cytokines like interleukin-1β and TNF-α, linked to joint pain, are reduced through ultrasound therapy.

• Continuous ultrasound (CU) - effective in chronic pain.
• Pulsed ultrasound (PU) - used for acute and subacute injuries, minimizing thermal effects.

Other methods include:

• Neuromuscular Electrical Stimulation (NMES)
• Interferential Current (IFC)
• Shortwave Diathermy (SWD)
• Heat Therapy (to reduce stiffness)
• Cryotherapy (to reduce swelling)

 

Therapeutic Exercises

Exercise is the cornerstone of physiotherapy for knee osteoarthritis. A well-designed program can strengthen muscles, improve flexibility, and enhance joint function while reducing pain. The program typically includes:

Strengthening Exercises

Isokinetic Exercise

Isokinetic exercise is effective in reducing inflammation, relieving pain, and increasing muscle strength, with eccentric exercises providing superior benefits over concentric ones for KOA patients.

• Effective for dynamic muscle strengthening, pain relief, and reducing disability in KOA patients.
• Decreases inflammatory markers (TNF-α, IL-6, C-reactive protein) in serum.

Isometric Exercise

Isometric exercise improves joint fluid quality, proprioception, balance, muscle strength and neuromuscular function, with similar benefits across genders.

• Enhances proprioception and coordination of quadriceps proprioceptors.
• Improves both dynamic and static balance in KOA patients.
• Strengthens muscles in both male and female patients, with a cross-training effect on the contralateral quadriceps.

Isotonic Exercise

Isotonic (dynamic) exercise involves muscle contraction with unchanged tension but changing muscle fiber length, causing joint movement. It is of two types:

• Isotonic Centripetal Exercise: Muscle shortens (e.g., jumping).
• Isotonic Eccentric Exercise: Muscle lengthens (e.g., squatting, walking downstairs).

 

Aerobic Exercise

Aerobic exercise has diverse benefits, including metabolic improvements and pain relief. Different intensities of aerobic exercise yield different therapeutic effects: low-intensity for severe KOA, high-intensity for mild KOA.

Examples of Aerobic Exercise:

It includes walking, jogging, cycling, skating, rhythmic exercises, aerobics, ball games, and rowing.

Benefits of Aerobic Exercise:

• Aerobic exercise improves cardiopulmonary function, reduces oxidative stress, promotes fat metabolism, and prevents muscle disuse atrophy.
• Enhances cartilage health by increasing cartilage oligomeric protein and glycosaminoglycan content, promoting cartilage repair and growth.
• Strengthens the immune system by activating T lymphocytes, enhancing immunity.
• Improves physical performance and quality of life in individuals with KOA.
• Provides therapeutic effects, including significant pain relief and improved quadriceps strength.

Neuromuscular Training

Neuromuscular exercise is a valuable therapeutic approach for KOA patients, particularly beneficial for those with specific alignment issues and for improving outcomes before and after surgical interventions.

It provides better long-term relief from swelling and stiffness than pharmacotherapy, while avoiding side effects of analgesics and anti-inflammatory drugs.

Balance and Proprioception Exercises

Proprioceptive training is crucial for addressing balance dysfunction and pain in KOA, especially in patients experiencing weight-bearing pain. Weakening and damage of knee structures contribute to decreased proprioception. Impaired proprioceptors lead to abnormal pain perception and limited joint functional ability.

These exercises challenges individuals to regain their center of gravity during destabilizing movements and reduce support base size, requiring feedback postural control.

Forms of Balance Training:

• Static balance training
• Dynamic balance training
• Balance instrument training
• Virtual Reality (VR) training

 

Gait Retraining

Assess the patient’s walking pattern to identify any abnormal compensations (e.g., limping, overloading one leg). Teach proper gait techniques to ensure even weight distribution and reduce stress on the affected knee. If necessary, suggest the use of a cane or walker to unload the knee joint during walking.

 

Aquatic Exercise for Knee Osteoarthritis

Aquatic exercise, through temperature stimulation and buoyancy, effectively improves the physical function and quality of life for patients with KOA. It is particularly advantageous for KOA patients with a high body mass index due to its weight-bearing reduction effects.

Benefits of Aquatic Exercise:

• Temperature stimulation & buoyancy improves motor dysfunction in patients.
• Buoyancy provides therapeutic effects by reducing weight-bearing stress.
• Faster reduction in knee stiffness compared to routine rehabilitation, progressive resistance aquatic exercise increases the thickness of medial femoral cartilage and improves. cardiopulmonary function

 Specific Exercise Types:

• Dance-Based Aquatic Exercise: Significantly enhances physical function and cardiorespiratory capacity in obese postmenopausal women, reduces post-exercise heart rate and fatigue.
• Aquatic Treadmill Exercise: Improves joint angular velocity and reduces arthritis-related joint pain.

Manual Therapy

Gentle mobilization techniques can be performed to improve joint movement and reduce stiffness in the knee. Techniques can include:

• Patellar Mobilization: Helps in reducing stiffness around the kneecap.
• Tibiofemoral Joint Mobilization: Can increase the range of motion and reduce pain by improving joint congruency.
• Soft Tissue Mobilization: Target surrounding muscles (quadriceps, hamstrings, calves) to reduce tightness and improve muscle flexibility.