The sport of rock climbing, be it recreational or competitive, is becoming more and more popular(1–3), yet there is little knowledge regarding the extreme footwear used, nor the injury profile of the lower limb(1). 98% of climbers wear excessively tight footwear and 91% experience foot pain while climbing (1). There is a perverse culture among rock climbers, that foot pain is a normal aspect of the sport(1). So much so, that an increase in climbing ability is seemingly impossible without some level of discomfort and the detrimental effects on the foot are often overlooked(1).
Rock climbing requires highly specialized shoes that are designed to maximize the climber’s ability to grip onto small areas, on real or artificial rock surfaces (2,4,5). They are flexible shoes, of varying shape, as seen in Figure 1 and 2, with “sticky” rubber soles (4). As for any shoe and any sport, shoe design and correct sizing are very important (1). The asymmetrical shape of these shoes increases the contact area of the foot, however, this results in the foot being forced into an unnatural position(3). The typical, recommended fit for these shoes is one size smaller than an athletics shoe(4). This enables a greater amount of control on tiny surfaces (4). Rock climbers, however, have a tendency to wear climbing shoes that are about 2.5 (UK) sizes smaller than their foot size and up to 4 (UK) sizes smaller than their street shoe size (1,3). As seen in Figure 3 and 4, some climbers wear shoes that are shorter than that of their feet(1)! There is also huge variation in the manufacturers’ sizing and designs(1). This variation creates unreliability and makes footwear fitment choices particularly difficult(1).
Figure 3. Comparison between a climber’s bare foot, his normal shoe and his climbing shoe, after McHendry et al (2015) and Buda et al (2015).
Figure 5. A typical rock climber’s foot with a) callus and joint deformity, b) Hagland’s deformity, c) brittle nails, d) dorsal callous and deformities of the lesser digits, after McHendry et al (2015)
Climbers are not aware of the risks and problems associated with their extremely tight footwear (1). This ill fitting footwear may not result in any immediate problems, but there are serious long term problems that may only manifest later in life(1).
Corns and callous, which are areas of abnormally thickened skin are evidence of poorly fitting shoes in general. This is made worse in extremely tight fitting shoes, where there is increased pressure and friction between the shoe and the skin(1). This is typically present on the top and bottom of the feet, especially the toes, as seen in Figure 5 A & D (1).
Lack of shoe length results in increased pressures at the back of the heel and the front of the foot (1). This results in the shoe cutting into the back of the heel, causing pain as a result of inflammation of the bursa between the Achilles tendon and the calcaneus (heel bone), which is known as retrocalcaneal bursitis, as shown in Figure 6 (3). It may also cause inflammation of the Achilles tendon itself (Achilles tendonitis)(3), or a bony enlargement of the heel bone, known as Haglunds deformity, as seen in Figure 5b (1).
A short shoe is also associated with deformities of the lesser toes, such as claw and hammer toes, as seen in Figure 5D and Figure 7 (1). Constrictive footwear results in the toes being bunched up. Eventually the toes remain in this position as the ligaments and tendons around the affected joints shorten.
There are many toenail issues associated with this sport and its tight shoes. The nails may either thicken (onychogryphosis), become brittle (Figure 5C), or lift from the nail bed (onycholysis) (1,3)
with the constant pressure of the very tight shoes. Ingrown toenails may also be the result of tight fitting footwear and/or poor nail cutting technique (4). Fungal nail infection (onychomycosis) is also a common problem among rock climbers(1,3). Fungus thrives in warm, moist and dark environments. These shoes offer the perfect environment for fungus as the rubber and synthetic materials of the shoes do not allow the foot to air and, they are warm and moist due to increased body temperatures and sweat during exercise. Other nail conditions seen in rock climbers as a result of their tight shoes include: splinter haemorrhages (1), which are small and subtle areas of bleeding under the nail, and subungal haematoma (1), which is a bruise or blood blister under the nail.