1. What Finger Pulleys Actually Do
Each finger has annular pulleys (A2, A3, A4) — small ligament bands that keep flexor tendons close to the bone.
Their functions:
- redirect tendon force
- prevent bowstringing (tendon lifting away from bone)
- stabilize DIP/PIP joints
- maintain efficient pulling mechanics
Pulley strength is highly sensitive to:
- shear load (sideways stress)
- dynamic spikes
- fatigue
- wrist collapse
- crimping angles
The A2 pulley takes the biggest load in climbing.
The A4 stabilizes the DIP joint.
The A3 is small but vulnerable in half-crimp transitions.
2. How Pulley Injuries Happen (Mechanics)
Pulley failure occurs when tendon force > ligament capacity.
This usually happens during:
1. Full Crimp at High Force
DIP joint hyperflexion (finger tip bends sharply) → massive A2 / A3 load.
2. Dynamic Catch in Crimp
Velocity × load = force spike.
3. Off-Axis Crimping
Force not aligned with finger → shear load ↑ → pulley stress ↑.
4. Wrist Collapse (ulnar deviation)
Wrist tilts inward → tendon line shifts → pulley tension ↑ by 30–50%.
5. Crimping in Fatigue
Stabilizers fail → pulleys absorb uncontrolled force.
6. Cold Fingers
Cold collagen = stiff, brittle, low-capacity.
3. Pain Pattern: What Pulley Injuries Feel Like
Pulley injuries have a distinctive pain signature:
- sharp pain at the base or middle of the finger
- worse in crimp positions
- pain when pressing on the pulley area
- swelling or thickening around the tendon
- “weak crimp” feeling
- pain during pull-through phase of moves
- sometimes a pop during injury event
If there was a pop + swelling → treat as at least Grade 2.
4. Injury Grading (Biomechanical, Not Medical Diagnosis)
This is a mechanical grading, not clinical.
Grade 1 — Pulley Strain
- no pop
- mild local pain
- hurts only during hard crimp
- no bowstringing
Grade 2 — Partial Tear
- possible pop
- swelling
- moderate pain during gripping
- strong pain in full crimp
- some tenderness on palpation
Grade 3 — Complete Tear
- audible pop
- immediate swelling
- visible bowstringing (tendon lifts)
- gripping extremely painful
- loss of force
Grade 3 needs medical imaging + supervised rehab.
Grades 1–2 follow the load model below.
5. Yellow & Red Flags
Yellow Flags (reduce load)
- local tenderness
- dull ache when crimping
- morning stiffness in finger
- pain only on small edges
Red Flags (stop training)
- sharp pain
- audible pop
- swelling
- inability to grip
- visible tendon lift
- strong pain with finger bending
If red → stop climbing and start load-controlled rehab.
6. Technique Errors That Overload Pulleys
These multiply pulley load dramatically:
1. Full crimp on holds where half-crimp is enough
Full crimp = highest A2 stress.
2. Overgripping
Flexor dominance → pulleys overloaded.
3. Wrist collapse
Changes tendon line → adds shear.
4. Hips too far from wall
Finger load ↑ because CoM (center of mass) is further out.
5. Catching dynos sloppily
Force spike + off-axis angle = pulley overload.
7. Immediate Actions After Pulley Injury (0–72h)
1. Load reduction (not total rest)
Rest decreases collagen stiffness → worse long-term outcomes.
2. Light isometrics (static holds at 20–30%)
Stimulates tendon + ligament healing without overloading.
3. Gentle mobility
Keep the tendon gliding smoothly.
4. No crimping
Open-hand only.
5. No dynamic movements
Avoid force spikes.
Pain should decrease with light movement → sign of safe loading.
8. Rehab Plan — The Three-Phase Model
This model follows tendon + ligament biology.
Phase 1 — Pain-Phase Isometrics (3–14 days)
Goal: reduce pain + stimulate safe collagen alignment.
- 3–5 reps
- 30–45s holds
- 20–40% intensity
- 1–2× per day
- on large edge or jug
Criteria to progress:
→ pain ≤3/10 in open-hand pulling
Phase 2 — Controlled Eccentrics (2–6 weeks)
Eccentric = slow lowering under tension.
Goal: realign collagen + increase tissue stiffness.
- 6–10 reps
- 3–5s lowering phase
- 3× per week
- open-hand only
- minimal pain (<3/10)
Criteria to progress:
→ can pull open-hand on mid-size edges without pain next day
Phase 3 — Progressive Loading (max strength return)
Follow 2–5% rule (small weekly increases).
- half-crimp first
- no full crimp until pain-free at half-crimp
- avoid dynamic moves early
- gradually return to smaller edges
Criteria to return to normal climbing:
→ no pain during gripping
→ no pain next morning
→ no swelling
→ consistent joint stacking
Full crimp reintroduction = final step.
9. Return-to-Climbing Protocol (Safe Sequencing)
- Open-hand only
- Larger edges (≥20 mm)
- Half-crimp on large holds
- Repeaters (low intensity)
- Max hangs (half-crimp)
- Small edges
- Full crimp reintroduction (only if completely pain-free)
- Dynamic climbing (last phase)
Most climbers rush steps 6–8 → re-injury.
10. Long-Term Prehab (5 min routine)
- 3× 20s open-hand isometrics
- 10 slow extensor curls
- 10 wrist pronation/supination
- 20s finger tendon glides
- 10 scapula depression/retraction
- technique check: wrist neutral on small edge
This reduces pulley stress dramatically.
11. When to Seek Professional Help
- visible bowstringing
- sharp pain persists beyond 1–2 weeks
- full crimp remains painful after 6+ weeks
- swelling returns
- nerve pain or tingling
- finger locking or catching
Better safe than sorry for Grade 3 patterns.