15.3 Mechanical Modalities (Traction, Compression, CPM)
Key Takeaways
- Acute or suspected DVT contraindicates intermittent pneumatic compression until the athlete is medically cleared; compressing a clot can embolize. Keep cuff pressure below diastolic blood pressure.
- Commonly taught traction doses: cervical trial about 10–15 lb, distraction about 20–30 lb (~7–10% body weight); lumbar stretch/spasm about 25% body weight, separation about 50% on a split table.
- Do not apply lumbar traction in pregnancy or to an unstable spine. Cervical traction: screen rheumatoid atlantoaxial instability, osteoporosis, TMJ dysfunction, and dentures (remove them; prefer occipital harness).
- CPM after surgery is physician-directed (often TKA). Long-term outcome evidence is modest; it is not a substitute for active rehabilitation. Massage guns are mechanical devices with nerve, bone, acute-injury, and DVT precautions.
- Trap: lumbar traction on a pregnant patient or unstable spine. Gravity-assisted inversion is still traction—same screens apply.
Quick Answer: Intermittent pneumatic compression (IPC) is contraindicated with acute or suspected DVT until cleared. Cervical traction for distraction is commonly about 20–30 lb; lumbar separation is often about 25–50% of body weight. Do not lumbar-traction a pregnant athlete or an unstable spine. CPM is physician-directed. Trap: lumbar traction in pregnancy or on an unstable segment.
Mechanical modalities apply force: compression, distraction, or passive motion. Task 0404 still applies—parameters, screens, and documentation—not a 'set it and walk away' cycle.
Intermittent compression and cold-compression units
IPC inflates a sleeve in distal-to-proximal chambers (sequential) or as a single chamber, then deflates so the veins refill. Clinic goals: post-traumatic or postoperative edema, residual-limb shaping, and, in medical settings, DVT prevention in immobilized patients. Athletic recovery boots are the same physics with marketing.
Commonly taught parameters (Cameron/Prentice-style; follow the device manual):
| Setting | Typical teaching range | Why it matters |
|---|---|---|
| Pressure, upper extremity | About 30–60 mmHg | Below diastolic blood pressure so arteries still fill |
| Pressure, lower extremity | About 40–80 mmHg | Athletic recovery units may go higher; still respect arterial disease and pain |
| On:off | Often about 3:1 (for example 90 s inflate / 30 s deflate) | Deflation is when arterial inflow and venous refill occur |
| Time | About 20–30 minutes (lymphedema protocols can be longer) | Recheck skin, fingers/toes, and symptoms |
Measure blood pressure first. A cuff above diastolic pressure is an arterial tourniquet with extra steps. Elevate the limb. Use a stockinette. Watch fingers and toes for color and sensation.
DVT is the headline contraindication. If a clot is present or reasonably suspected (unilateral calf swelling, warmth, positive Wells-type picture, recent surgery plus dyspnea), do not compress that limb until vascular medicine has ruled out or treated the clot. IPC on an existing DVT can embolize. After a cleared, treated DVT, follow the physician—do not freelance.
Other IPC stops: decompensated heart failure / pulmonary edema (you are pushing fluid centrally), acute infection or open wound in the sleeve, acute fracture you are not ready to compress, compartment syndrome, and severe peripheral arterial disease. Game Ready–style cold-compression units add cryotherapy contraindications (Raynaud, cold urticaria, regenerating nerve) on top of the DVT rule. They do not get a free pass because the water is cold.
Traction: cervical versus lumbar, mechanical versus gravity
Traction applies a distractive force along the long axis of the spine. Proposed effects, as taught: separate vertebrae a few millimeters, unload a disc bulge, gap facet joints, stretch muscle and ligament, and reduce radicular compression. Evidence for lasting disc reduction is mixed; many athletes get temporary relief. Dose it as a trial, not as a cure for every backache.
Mechanical traction uses a motorized unit and harnesses (occipital/chin for cervical; thoracic and pelvic belts for lumbar) on a table, often a split table for lumbar so friction does not eat the force. Manual traction is the AT's hands—useful as a test dose. Gravity-assisted traction (inversion table, hanging from a stall bar, some home pneumatic devices) uses body weight. It is still traction. Pregnancy, unstable spine, uncontrolled hypertension, and glaucoma/orbital issues still matter. Inversion is not 'natural' and therefore safe.
Textbook-conventional forces
These are commonly taught Kisner/Colby and Prentice numbers, not a license to yank.
| Goal | Cervical (typical teaching) | Lumbar (typical teaching) |
|---|---|---|
| First-visit trial / muscle spasm | About 10–15 lb (do not start at 30 lb on a 110-lb gymnast) | About 25% of body weight (enough to beat table friction on a split table) |
| Joint distraction / disc | About 20–30 lb, often framed as ~7–10% of body weight; many sources cap cervical near 30 lb | About 50% of body weight (range often ~30–60% as tolerated); older texts quote 65–200 lb depending on body size |
| Angle | Upper cervical nearer neutral; lower cervical often 20–30° flexion | Flexion bias (supine 90/90) for stenosis/facet; some disc protocols use prone/neutral |
| Mode | Intermittent (often ~3:1 hold:rest) common for disc; static sometimes for spasm | Intermittent common for disc herniation teaching; static for some stiffness protocols |
| Time | About 10–20 minutes | About 10–20 minutes |
Position and pathology. A locked facet (acute wry neck, sharp local pain, guarded rotation) may respond to a gentle flexion-and-rotation bias or a small distractive trial—not a maximum-poundage yank. A disc herniation with progressive neurologic deficit, saddle anesthesia, or myelopathy is not a traction candidate; that is a medical emergency. Midline massive herniation and worsening radiculopathy are precautions/contraindications in most EPA lists. If symptoms peripheralize (pain moves farther down the limb), stop and regress—that is the mechanical-diagnosis cousin of a failed traction trial.
Traction screens the exam loves
Do not apply traction (especially lumbar) in:
- Pregnancy (lumbar belts over a gravid abdomen; ligamentous laxity; this is a hard teaching contraindication)
- Unstable spine (fracture, acute severe sprain, postsurgical instability, high-grade spondylolisthesis as directed by the physician)
- Rheumatoid arthritis of the cervical spine (atlantoaxial instability—a chin-strap pull can be catastrophic)
- Osteoporosis / osteopenia sufficient to fracture
- Spinal infection, malignancy, myelopathy, uncontrolled hypertension, severe anxiety/claustrophobia that makes the harness unsafe
Cervical-specific: TMJ dysfunction and dentures. A mandibular (chin) strap loads the jaw. Remove dentures, ask about TMJ, and prefer an occipital harness that unloads the chin. Vertebral-basilar insufficiency symptoms (dizziness, drop attacks, visual change) with cervical positioning mean stop.
Herniation versus facet is a precaution story, not a single poundage. Facet-oriented pain often likes flexion and intermittent motion. Acute, angry disc with neurological worsening does not get 50% body-weight lumbar traction because a protocol PDF said 'disc.'
CPM and percussive devices
Continuous passive motion (CPM) is a motorized cradle that cycles a joint through a physician-set arc, classically after total knee arthroplasty and some cartilage or ACL procedures. Salter's animal work argued that motion nourishes cartilage. Human Cochrane-style reviews after TKA show at most small, short-term ROM differences of questionable clinical importance. Teach it as physician-directed adjunctive motion, not as a replacement for quadriceps activation, swelling control, and gait. Set the device to the written ROM, check skin and incision, and do not crank flexion past the surgeon's lock because the athlete is 'tough.'
Massage guns (percussive/vibration devices) are mechanical modalities. Limited high-quality outcome data support them as recovery toys more than as disease-modifying therapy. Precautions still count: do not percuss over acute injury or fracture, DVT, bony prominences, the anterior neck, the spine/spinous processes with aggressive force, impaired sensation, anticoagulation (bruise risk), or an open area. A gun on a calf 'knot' that is actually a DVT is a disaster.
Putting the mechanical cluster together
Screen first: pregnancy, DVT, instability, RA neck, osteoporosis, pacemaker (if combining with e-stim), skin, and cognition. Then pick the force that matches the goal—edema emptying is not vertebral separation, and a CPM arc is not traction. Reassess symptoms during the bout; peripheralizing pain, dyspnea, calf pain, jaw pain, or dizziness ends the session.
Exam trap: lumbar traction on a pregnant patient or an unstable spine. A second trap is treating gravity-assisted inversion as exempt from the same list. A third is using IPC to 'treat' a DVT. Mechanical force is only as safe as the screen.
A 28-year-old athlete in the second trimester of pregnancy has mechanical low-back pain without red-flag neurologic loss. The clinic owns a motorized lumbar traction table and an inversion unit. What is the appropriate action?
Which statement about intermittent pneumatic compression is consistent with safe athletic-training practice?
Which description of mechanical-modality parameters is accurate as commonly taught?