The half crimp grip, also called an open hand crimp, is the same hand and finger grip for using small handholds when you climb as the full crimp, except that your thumb doesn't lock on top of your index finger after your hand is placed on an edge handhold.
Half Crimp is Weaker Than Full Crimp
The half crimp grip is more comfortable, ergonomic, and less stressful on your finger joints than the full crimp grip. It is, however, a weaker grip than the full crimp since your thumb isn't pressing downward and it is less secure for moving upwards. The half crimp, like the full crimp, is best used on narrow edges where you can place the pads of all four on your fingertips.
Use Half Crimps to Avoid Injury
Use the half crimp grip whenever possible instead of the full crimp and your fingers will thank you. The full crimp grip places extreme forces on the tendons and joints of your fingers, leading to long-term damage if you use it regularly on the rocks. The half crimp, however, builds hand and forearm strength as well as contact strength for hanging onto sloping handholds. Train the half crimp in gym workouts such as bouldering to increase your crimp strength-just don't overdo the training and injure your fingers.
