A dislocation occurs when a bone is wrenched out of its natural position. Typically a finger (especially the thumb), a shoulder, or the jaw are affected. On the hiking trail, a knee or a hip also can become dislocated, especially after a fall, the major cause of dislocations.
To avoid a dislocation, don’t fall, make cross-body movements, lift too heavy of objects over one’s head, or slam oneself against solid objects, like a boulder. Kids having fun often do these things.
You can tell if someone has dislocated a bone by their contorted limbs, swelling around the affected joint, a pain that worsens with motion, and bruising.
To treat, have the victim support the injured joint, and immobilize it using a bandage or a sling. If the shoulder is dislocated, secure it against the chest using a bandage. Treat the victim for shock and seek medical attention. Do not attempt to reposition the dislocated bone into its socket, as this may cause further injury.
Read more about day hiking with children in my guidebook Hikes with Tykes.