6.3 Mechanical Traction, Intermittent Compression, and Shockwave

Mechanical Traction, Intermittent Compression, and Shockwave

These treatments deliver force in different ways. Spinal traction applies distraction. Intermittent pneumatic compression (IPC) cycles pressure around a limb. Focused shockwave and radial pressure-wave devices apply short pressure pulses to a targeted region. Start with the indication and the outcome that would justify treatment.

1. Mechanical Spinal Traction

Traction applies an external distraction force to the spine. Mechanical devices can provide a sustained pull or alternate higher and lower forces. The position, angle of pull, fixation, harness and patient tolerance affect the load and response.

An imaging study measured an increase in cervical foraminal cross-sectional area during neutral-position distraction. A temporary change during a test does not establish lasting decompression or identify a required treatment dose. A small lumbar study measured pressures below −100 mmHg during a particular vertebral axial decompression procedure. That result was specific to the tested setup and does not show that routine lumbar traction draws herniated material back into the disc. Pain relief can occur without establishing a structural mechanism.

Cervical traction

The APTA Orthopaedic Section neck pain guideline includes intermittent mechanical cervical traction combined with other interventions for chronic neck pain with radiating pain. An appropriate exercise plan and reassessment of neurological findings remain important.

Fritz and colleagues studied a supine protocol beginning at 12 lb of pull and approximately 15° of cervical flexion, with angle adjusted for comfort and force adjusted according to symptoms and tolerance. The sessions used 60 seconds of pull and 20 seconds at half the pull force for 15 minutes, alongside exercise. This is a trial protocol, not a force, angle or timing rule for a particular root level. A seated over-door device has a different setup and operating range. Check fit and follow the equipment instructions. Record the device, position, pull and relaxation forces, timing and patient response.

Lumbar traction

NICE NG59 advises against traction for low back pain with or without sciatica. The APTA low back pain guideline recommends against mechanical traction for chronic low back pain with leg pain when added to other interventions. A later open-label hospital trial found more patients reaching at least a 25% reduction in radicular pain after one month when traction was added to medical care for selected patients with concordant disc herniation. The trial used supine continuous traction for 15 minutes, with a device-specific progression from a 15 kg to a 24 kg load setting. The result does not establish routine outpatient benefit, a universal force threshold or a disc-reduction mechanism.

A split table can reduce the resistance to movement of the table section under the patient. Cable tension is not the same as the load at an individual spinal segment. Do not use a percentage of body weight as proof of segmental distraction. In a setting where an appropriately selected protocol is used, document the position, force, duration and symptom response and follow the local pathway.

2. Traction Safety and Reassessment

Withhold traction and arrange appropriate evaluation when the history or examination suggests fracture, spinal instability, spinal cord compression, local spinal infection or a lesion that compromises bone strength. Review bone fragility, postoperative restrictions, cardiopulmonary tolerance and whether the harness and position are suitable. A negative Sharp–Purser or alar ligament test cannot clear suspected instability. Avoid provocative testing when the presentation warrants medical or trauma assessment.

Apply the cervical vascular reasoning in Joint Mobilization and Manipulation. Clear vascular signs call for immediate medical referral. Use focused, nonprovocative examination only when appropriate in a subtle presentation. Withhold cervical traction while serious pathology remains a concern. Sustained extension–rotation does not clear a patient for traction.

Compare symptom distribution, relevant tasks and neurological findings before and after treatment. A change in symptom distribution can inform reassessment. Stop if symptoms spread distally or new neurological findings appear. Escalate new or progressive neurological compromise through the appropriate pathway.

3. Intermittent Pneumatic Compression

An IPC pump inflates and deflates one or more chambers in a fitted sleeve or cuff. The chamber order, cycle, pressure and treatment time depend on the device and purpose. Cyclic leg compression can increase venous flow while the device is in use. In edema care it can assist fluid movement as part of a longer-term plan.

A home lower-limb lymphedema feasibility study used a specific pump at 40 mmHg for 35 minutes twice daily. That is a device and study example. A brachial diastolic pressure is not a setting rule for a limb pump. Select settings from the indicated device and clinical protocol after considering perfusion, sensation, skin condition, fit and tolerance. Document the sleeve and settings and inspect the limb for pain, skin injury, numbness, color change or proximal swelling. Stop and reassess concerning changes.

New unilateral swelling with pain or warmth can warrant DVT assessment before an edema treatment. Withhold an unsupervised pump trial while a new clot is suspected. APTA's VTE guideline advises against routinely recommending mechanical compression for newly diagnosed lower-extremity DVT. Follow the treating team's plan and the device labeling. Decompensated heart failure, pulmonary edema, acute infection, or impaired limb perfusion warrants medical assessment before initiating a routine pump. Do not apply the contraindications for sustained compression stockings as a universal rule for IPC. Stable heart failure or arterial disease requires an indication- and device-specific decision.

4. Focused Shockwaves and Radial Pressure Waves

A pressure pulse transfers mechanical energy. Mechanotransduction describes conversion of a mechanical stimulus into a biological response. Animal studies report responses such as changes in vascular markers at the tendon–bone junction. Cavitation may occur under particular pulse conditions. Neither mechanism establishes how much tissue repair occurred in a patient. Follow pain, load tolerance and function rather than using a proposed cellular effect as a clinical outcome.

Indication and guidance matter. For persistent plantar fasciopathy, some guidance considers a shockwave or pressure-wave intervention after appropriate exercise and education have failed to help. Gerdesmeyer's radial trial used 2,000 impulses per session over three sessions in a selected chronic refractory group. A later trial found no added pain benefit of its radial protocol over advice and customized orthoses. Discuss the uncertainty and match the protocol to the device and indication. NICE HTG200 calls for special arrangements for governance, consent and audit or research for refractory plantar fasciitis.

The 2025 APTA rotator cuff guideline permits considering extracorporeal shockwave for calcific tendinopathy and recommends against it for noncalcific rotator cuff tendinopathy. NICE HTG645 restricts the calcific shoulder procedure to research in its setting. This difference concerns the same indication under different practice guidance. Follow the applicable local pathway. Bone nonunion is a separate specialist indication and does not use a generic tendon regimen.

Check device-specific exclusions, target depth and structures in the treatment field. The ISMST consensus distinguishes radial or low-energy focused procedures from high-energy focused procedures. Examples include avoiding malignancy, a fetus or implanted pacemaker or defibrillator in the treatment field, and avoiding lung tissue and significant coagulation disorders with high-energy focused use. Verify suitability before treatment and discuss expected response and adverse effects, such as transient pain or bruising.

5. Worked Clinical Comparison

Radiating neck pain. A patient with persistent unilateral arm symptoms and a stable neurological examination participates in a progressive exercise program. The history and examination do not suggest fracture, instability, cord compromise or a cervical vascular disorder. If an adjunct trial of intermittent traction is appropriate, select a tolerable position and device-specific dose, then check arm symptoms and a patient-selected task. New weakness or worsening distal symptoms calls for stopping and reassessing. An immediate improvement does not establish disc reduction.

Persistent plantar heel pain. A patient has first-step pain after several months and still cannot tolerate a full standing shift despite an appropriate exercise and education program. Confirm the working diagnosis and consider alternative sources of heel pain before discussing a procedure. If radial pressure-wave treatment is available and appropriate under local guidance, discuss the variable trial results. Record the device-specific regimen and monitor first-step pain and standing tolerance while maintaining active rehabilitation.