Classification
| Element |
Detail |
| Category |
Non-Swedish — Cross-Fiber Friction |
| Subcategory |
With-fiber (longitudinal) friction |
| FOMTRAC |
PC 3.2h |
| Fritz method |
Friction (parallel to fibers) |
Purpose
- Separate longitudinal adhesions between adjacent muscle fibers or fascial layers
- Promote realignment of collagen fibers along the line of mechanical stress
- Release restrictions in the fascial plane parallel to the muscle fiber direction
Mechanism
The treating finger or thumb engages the skin and underlying tissue, then moves it along the fiber direction without sliding over the skin. This creates a shearing force between adjacent tissue layers (fiber-to-fiber, muscle-to-fascia), mechanically separating longitudinal adhesions that restrict normal fiber glide. Unlike Cyriax DTF (which shears perpendicular to fibers), longitudinal friction separates fibers that are stuck together side by side. The sustained linear friction stimulates fibroblast activity along the line of force, promoting organized collagen deposition that restores normal inter-fiber mobility.
Indications
- Longitudinal adhesions within muscle bellies (fibers stuck to adjacent fibers)
- Fascial restrictions running parallel to muscle fibers
- Post-strain adhesions where fibers healed in a shortened or adhered pattern
- Hamstring strain (subacute/chronic) with palpable longitudinal restriction
- Quadriceps contusion with intramuscular adhesion
- Chronic muscle tension with reduced fiber glide on palpation
- Scar tissue along a muscle's longitudinal axis
Contraindications
- Acute inflammation (first 48-72 hours)
- Acute muscle tear at the treatment site
- Open wounds or infection
- Anticoagulant therapy (modify pressure)
- Over superficial neurovascular structures
Effects
Immediate:
- Separation of adhered fibers; improved inter-fiber glide
- Local hyperemia along the treated fiber pathway
- Improved palpable tissue mobility in the fiber direction
Cumulative (repeated sessions):
- Progressive reduction in longitudinal adhesion density
- Restored normal fiber glide throughout the muscle
- Improved muscle contractile efficiency (fibers slide independently)
Risks and Side Effects
- Post-treatment soreness (24-48 hours)
- Bruising if applied too aggressively
- Confusion with muscle stripping: Longitudinal friction does NOT slide on the skin; if you are gliding, you are stripping, not frictioning
- Skin irritation if lubricant is present (lubricant eliminates the friction effect)
Expected Outcomes
Short-term (within session):
- Improved fiber glide on re-palpation
- Reduced palpable restriction along the treated fibers
- Local warmth (hyperemia)
Medium-term (over multiple sessions):
- Restored full fiber mobility
- Improved muscle length and contractile function
- Reduced provocation on stretch testing
Execution
| Step |
Detail |
| Client position |
Position that allows comfortable access to the target muscle; muscle in a neutral or slightly shortened position |
| Remove lubricant |
Wipe the area clean |
| Hand placement |
Reinforced thumb or fingertip on the target fibers |
| Action |
Engage the skin and underlying tissue; move parallel to the fiber direction in short strokes; the skin moves with the finger (no slide) |
| Amplitude |
2-4 cm along the fiber length |
| Rate |
1-2 strokes per second (slower than DTF) |
| Duration |
1-3 minutes per site |
| Depth |
Moderate to deep — must reach the adhesion layer |
| Lubricant |
None |
Parameters
| Parameter |
Range |
Clinical Reasoning |
| Amplitude |
2-4 cm |
Longer than DTF because the friction line runs along the fiber, not across it |
| Rate |
1-2 strokes/sec |
Slower than DTF to allow sustained shearing between adjacent layers |
| Duration |
1-3 min per site |
Shorter than DTF because longitudinal adhesions often respond faster |
| Depth |
Moderate to deep |
Must reach the inter-fiber plane where adhesions reside |
| Direction |
Along fiber direction |
Parallel to the line of pull of the muscle fibers |
Clinical Notes
- Most common error: Sliding on the skin and calling it longitudinal friction. If your finger moves over the skin surface, you are performing muscle stripping (a Swedish technique), not friction. The defining feature of all friction techniques is that the skin moves with the finger.
- How to know it is working: Re-palpate the fibers after 1-2 minutes. The previously "stuck" or "gritty" feeling between fibers should feel smoother. The client may report decreased stiffness.
- When to use this vs. Cyriax DTF: Use longitudinal friction when the adhesion runs along the fiber plane (fibers stuck to each other side by side). Use DTF when the adhesion crosses the fiber plane (e.g., scar bridging across a tendon).
- Clinical pearl: Longitudinal friction pairs well with Cyriax DTF at the same site — friction perpendicular to fibers first (break cross-links), then along fibers (restore inter-fiber glide). This two-direction approach addresses both adhesion patterns.
Verbal Script
> "I'm going to apply friction along the direction of the muscle fibers. My finger won't slide on your skin — it will move the tissue underneath. You may feel a stretching or pulling sensation. Let me know if the pressure is too much."
Distinguishing Features
| Feature |
Longitudinal Friction |
Muscle Stripping |
| Skin slide |
No — skin moves with the finger |
Yes — tool glides along the skin surface |
| Lubricant |
None |
Required for the glide |
| Speed |
1-2 strokes/sec at one site |
Slow glide (1 inch per 2-3 sec) along full muscle length |
| Coverage |
2-4 cm at one specific adhesion |
Full length of the muscle (origin to insertion) |
| Primary mechanism |
Mechanical separation of inter-fiber adhesions |
Locating and releasing taut bands; circulatory flushing |
| Feature |
Longitudinal Friction |
Cyriax DTF |
| Direction |
Along (parallel to) fibers |
Perpendicular to fibers |
| Adhesion type |
Fibers stuck together side by side |
Cross-links bridging across fibers |
| Tissue positioning |
Less strict |
Cyriax positioning rules apply |
Key Takeaways
- Longitudinal friction moves skin and tissue along the fiber direction without sliding, separating fibers that are adhered side by side
- Distinguished from muscle stripping by the absence of skin slide and lubricant — if your finger glides on the skin, it is stripping, not friction
- Distinguished from Cyriax DTF by direction: longitudinal friction runs parallel to fibers; DTF runs perpendicular
- No lubricant, 2-4 cm amplitude, 1-3 minutes per site; pairs well with DTF for comprehensive adhesion treatment
- Best indicated for longitudinal adhesions from chronic strain, post-injury scarring, or restricted inter-fiber glide
