What are the recommendations for physical therapy in patients with bone metastases (bone mets)?

Physical Therapy for Patients with Bone Metastases

Physical therapy is safe and beneficial for patients with bone metastases when preceded by mandatory risk stratification using validated scoring systems (SINS for spine, Mirels' for long bones), with exercise programs targeting 150 minutes/week of moderate-intensity aerobic activity plus resistance training 2-3 times weekly, while avoiding high-impact activities and direct tumor site manipulation. 1, 2

Mandatory Pre-Exercise Risk Assessment

Before initiating any physical therapy, fracture risk must be quantified using validated tools 1, 2:

For spinal lesions:

• Use the Spinal Instability Neoplastic Score (SINS) 1, 2
• SINS ≤6: Stable, safe for exercise 1
• SINS 7-12: Potentially unstable, requires modified approach 1
• SINS ≥13: Unstable, absolute contraindication without surgical stabilization 1, 2

For long bone lesions:

• Use Mirels' score 1, 2
• Score ≤7: Low risk, safe for exercise 1
• Score 8: Moderate risk, requires caution 1
• Score ≥9: High risk, contraindication without surgical stabilization 1, 2

Absolute contraindications to physical therapy include: 1, 2

• Acute spinal cord compression 1
• Severe hypercalcemia 1, 2
• Active infection (avoid until asymptomatic >48 hours) 1
• SINS ≥13 or Mirels' ≥9 without surgical stabilization 2

Evidence-Based Exercise Prescription

Aerobic exercise: 1, 2

• Target 150 minutes per week of moderate-intensity activity 1
• Preferred modalities: walking, stationary cycling, swimming 1
• These activities minimize skeletal stress while maintaining cardiovascular fitness 1

Resistance training: 1, 2

• Frequency: 2-3 sessions per week 1
• Focus on unaffected skeletal areas 1
• Begin with isometric exercises and low resistance/body weight exercises 1, 2
• Progress gradually based on tolerance 1

For patients with severe fatigue: 1

• Limit to light exercises only 1
• Avoid high-intensity activities 1

The safety profile is excellent—studies demonstrate that exercise-related pathological fractures are rare, with no increased fracture incidence compared to control groups 3, 4, 5. A 2023 review of 26 trials found only three serious adverse events, none likely related to bone metastases 3.

Location-Specific Exercise Modifications

For appendicular (limb) metastases: 1

• Avoid deep hip flexion/extension with acetabular or femoral head involvement 1
• Avoid extremes of range of motion with shoulder metastases 1
• Modify weight-bearing activities based on lesion location 1

For axial (spine) metastases: 1

• Avoid excessive spinal flexion, extension, and torsion 1
• Avoid axial loading maneuvers 1
• Emphasize postural alignment and controlled movement 1

Functional and Balance Training

Essential components for maintaining independence: 1, 2

• Gait training to optimize walking mechanics 1, 2
• Transfer training for bed-to-chair and other transitions 1, 2
• Balance exercises to prevent falls 1, 2

Assessment tools: 1

• Single leg balance test 1
• Timed up-and-go test 1

These functional interventions improve physical function, muscle strength, and quality of life while maintaining safety 2, 5.

Multidisciplinary Integration

Physical therapy must be coordinated within a multidisciplinary tumor board that includes: 6, 1, 2

• Medical oncology 6, 1, 2
• Radiation oncology 6, 1, 2
• Orthopedic surgery 6, 1, 2
• Rehabilitation specialists 1, 2

Ongoing monitoring requirements: 1

• Regular review of new bone pain 1
• Serial imaging evaluation 1
• Continuous modification of exercises based on patient tolerance and risk assessment 1

Adjunctive Supportive Measures

Bone-targeted therapies to reduce skeletal-related events: 6, 1

• Denosumab 120 mg subcutaneously every 4 weeks 6
• Zoledronic acid 4 mg intravenously every 3-4 weeks 6
• These agents delay skeletal complications and reduce pain 1

Pain management: 6, 1

• Single-fraction radiotherapy (8 Gy) for painful bone metastases 6, 1
• Response rates of 70-80% for pain relief 6
• Analgesic therapy following WHO guidelines 1

Nutritional support: 1

• Calcium and vitamin D supplementation are essential 1

Critical Pitfalls to Avoid

Never initiate exercise without validated risk assessment scores—this is the most common error that compromises patient safety. 1, 2

Additional contraindications: 1, 7

• Do not apply heat, ultrasound, or massage directly at tumor sites 1, 7
• Avoid modalities that increase local blood flow at metastatic sites (thermotherapy, certain electrotherapy options) 7
• Do not prescribe high-impact or high-intensity exercises without proper screening 1

Delivery Method and Compliance

Physical therapy can be delivered safely through in-person, remote, or mixed supervision 3:

• Remote exercise delivery achieves 80.3% compliance, comparable to in-person supervision 3
• Nine of 26 trials (34.6%) successfully utilized unsupervised exercise sessions 3
• This flexibility improves access for patients with transportation or mobility limitations 3

Monitoring and Progression

Continuous surveillance is required: 1

• Increased monitoring of mobility and activities of daily living 1
• Regular functional capacity assessments 1
• Immediate cessation of exercise if new bone pain develops 1
• Re-evaluation with imaging if symptoms change 1

The evidence consistently demonstrates that rehabilitation of patients with bone metastases can be safely accomplished with low risk of pathological fractures, while achieving satisfactory outcomes in pain control, physical function, and quality of life 2, 5. The key is systematic risk stratification before exercise initiation and ongoing multidisciplinary coordination throughout treatment 1, 2.