Pulley Injuries : The Science

Injury
Hands are complex and there are lots of bits that have the potential to be injured, particularly when climbing as it places large forces through some pretty small bones and tendons. Broadly injuries fall into the categories of pulley ruptures (accounting for ~26% of injuries), PIP_joint (proximal interphalangeal) injuries where lumbrical tears may occur (~24% Bollen et al. 1990), collateral ligament and capsular injuries as well as fractures and breaks. Its well known that wearing rings when climbing carries a huge risk of de-sheathing and should not be done.

Pulley Injuries
These are the most common form of injuries climbers sustain, particularly when training regularly on finger or campus boards. They occur mostly in the ring finger and around 8% are grade IV injuries (where more than one complete pulley rupture) (Klauser et al. 2002, Schöffl et al. 2003). Grade IV injuries are more severe and bowstringing should be obvious clinically. The distribution of finger injuries tends to reflect the use and strength of the fingers themselves (Schöffl et al. 2006).

(NB - Table awaiting revision as percentages seem strange)

Whether imaging by Ultrasound Scan (USS) or Magnetic Resonance Imaging (MRI) is essential to diagnosis is debatable.

Recovery
There are few in-depth studies on how rehab should be performed with most studies looking at how 4-6 weeks rest, then taping and slow introduction to climbing affected recovery.

21 climbers reviewed after pulley injury (mean of 3.46 years, 0.25 to 18 years range). Comparison of strengths of fingers performed after 2 days rest. 10 minutes specific warm up, then 10 minutes rest, then test. Assessed by pulling on 2cm, rounded edge and assessing drop in weight from body weight. Measured for individual fingers (index, middle, ring), then index/middle/ring together crimped and open. Comparison to uninjured side, plus other statistical analysis. Injury distribution:

41% of injured fingers also noted to have restricted movement in PIPJ (5-10 degrees in most) Injured fingers showed same strength as uninjured fingers at 1 year.

Summary

No analysis done before 12 months, so unclear when full strength achieved. No standardised rehab program, thus unclear which approach best.

Taping
The effect of circumferential taping on flexor tendon pulley failure in rock climbers. Warme WJ, Brooks D. Am J Sports Med. 2000 Sep-Oct;28(5):674-8. 9 pairs of cadaveric hands aged 20-47yrs. Placed in a jig to recreate the crimp position. 2 fingers of each hand reinforced with tape (3 turns)- opposite fingers of each hand pair. FDS and FDP distracted to pulley failure point. A2 failed simultaneously with A3 and A4 in 55% of fingers. Statistical comparison of 22 pairs of fingers showed no improvement in strength with taping. Single pulley failure rates:

Biomechanical effectiveness of taping the A2 pulley in rock climbers. Schweizer A. J Hand Surg . 2000 Feb;25(1):102-7. In vivo study to assess bowstringing in fingers, along with the force of bowstringing in crimp grips. 16 fingers assessed using 2 types of taping. Taping over A2 reduced bowstringing by 2.8% and reduced force by 11% Taping over distal end pf proximal phalanx reduced bowstringing by 22% and absorbed 12% of force.

Impact of taping after finger flexor tendon pulley ruptures in rock climbers. Schoffl I, Einwag F, Strecker W, Hennig F, Schoffl V. J Appl Biomech. 2007 Feb;23(1):52-62. Assessment of H-taping and its ability to reduce the bone-tendon distance. USS assessment of 8 subjects with A2 rupture and multiple pulley ruptures of A2 and A3. Assessment of bone-tendon distance. H taping reduced bone-tendon distance by 16%, whereas circumferential taping did not reduce it. Strength improved by 13% in crimp position, none in open handing, using H taping.

GCW's Summary
Well, who knows. The cadaveric study has flaws- altered biomechanics from freezing, potential problems with testing methods etc: Fingers tested individually, with no thumb involvement- not true to most climbing grips. Frozen hands, thus tendon elasticity reduced possibly altering the results. Flexor chiasm function is complex and was not taken into account in this model, which may confound findings. The number of fractures (31.9%) raises concerns as to the nature and technique of loading of the fingers. Having said that the Strecker study appears to agree that there is no increase in strength with circumferential taping. Some may argue that this is observer bias from the inventor of the H technique. Basically, tape is cheap and likely does no harm if used for shorter (under 6 month) periods in rehab, I can’t see a problem with its use.

Other, non-SCIENCE stuff
Dave MacLeod : Pulley Injuries


 * Suggests use varied grip styles.
 * Variable approach to taping- states evidence shows no benefit whilst stating taping increases pulley strength by 12%.
 * Suggests rest of 1-3 weeks after pulley injury, until finger moves through normal range without pain.
 * After this, build up gradually but stop if you get pain, climbing open handed.
 * Ice the injured finger- this is well supported in other injury types.
 * No specific return to climbing protocol.

Dave MacLeod : Problems with Lay-off

Erik J Horst


 * Rest, ice, take NSAIDs (eg Ibuprofen) if swollen. Stop once swelling settles.
 * Light exercise when pain reduces.
 * Heated pad application 10 minutes, 3 times per day. Stop the fags, Jim.
 * Gradual return to climbing.
 * Return to full power climbing if not painful. Continue with taping for several months.

Other sites suggest similar regimes, equally vague.

GCW’s Recommendations
If you suspect you have sustained a pulley injury, stop climbing. If you are unsure of what you are doing, go and see somebody that has experience of treating these injuries. Rest the finger, apply ice for up to 10 minutes at a time to reduce swelling. NSAIDs have minimal evidence base, and have been shown to slow healing in other bony and tendon/ligament injuries. Personally, I avoid them but there’s no good SCIENCE to support me. There’s no good evidence that taping improves strength, but it’s cheap and easy so I personally would use it initially in the return-to-climbing phase. I’d try to reduce use and stop by 6 months. Return to climbing is the area with no evidence. I personally would suggest rest of 2-3 weeks, then reassess. During this initial period I’d do gentle movement exercises- finger flexion mostly, within limits of pain, plus gentle extension to (but not past) neutral. Once a full range of movement is painless, I would suggest beginning active rehabilitation whilst using taping. Now the lack of evidence kicks in and guessing starts. Open handing has been shown to reduce pulley stress, so a return to gentle climbing (openhanded style) would seem reasonbable. After another 3 weeks (studies have shown that collagen tissues need this time to adjust) you could move on (assuming there’s no pain) to the crimp grip. Full strength is regained at 12 months, although no studies have looked to see if this occurs earlier. In my experience, ligamentous/tendon recovery is complete by 6 months. Hence, I’d (tentatively) suggest a return to normal climbing by then (if painfree).

Links
www.climbinginjuries.com

Dave MacLeod : Pulley Injuries

Dave MacLeod : Avoiding Pulley Injuries - The Hard & Easy Ways

Dave MacLeod : Injuries - The problem with Lay-off

Finger Yoga

Thomas Bond (Physiotherapist) : Finger Injuries, Symptoms and Management

Articles from Dr Julian Sanders (includes specific information on finger/pulley injuries)