Author Pam Versfeld
Hypermobility occurs in all the joints of the hand. Depending on the degree of compliance in the connective tissue, some joints become less hypermobile (stiffen) with age, while others tend to remain very lax.
Hyperextension of IP joints of the thumb
This is one movement that does not seem to stiffen up with age.
Notice the increased ROM at both the IP and MCP joints of this child's thumb.
Also notice the typical hyperextension of the proximal but not the distal IP joints when the fingers are extended.
Hypermobility of the MP joint of the thumb is sometimes associated with reduced range of movement at the CMP joint of the thumb.
This combination of laxity of the at the M-P joint and decreased range at the C-M joint leads to increased stress on the M-P joint in actions that require wide range of extension or abduction of the thumb.
Hyperextension of the distal IP joints of the fingers
Hyperextennsion of the distal IP joints of the fingers is particularly noticeable in tasks that require application of force by the finger pads, or between the finger and thumb pads.
Children with hypermobile fingers who apply excessive force on the pencil shaft tend to hyperextend the distal IP joint when writing.
An adapted pencil grip avoids stressing the IP joints of the fore and middle fingers.
To avoid stressing the IP joint of the fore and middle fingers children can be encouraged to adopt a thumb adduction grip.
This grip allows the pencil shaft to be stabilized between the thumb and the side of the forefinger while still allowing free movement of the fingers to manipulate the end of the pencil.
Tendency to actively hyperextend the proximal IP joints
The proximal IP joint is hyperextended with flexion of the distal IP joint.
This may occur when the fingers are being extended. Or when the fingers grasp an object.
Extension of the M-P joints to > 900 or is common
Joint laxity in the M-P joint of the fingers expose children to the risk of finger injuries when catching a ball.
Flexion of the wrist
When the wrist is flexed the thumb can be bent to touch the forearm.
Full range of this movement is often lost as the child gets older, but is maintained in some individuals into adulthood.
Strengthening the muscles of the hand
Muscle strengthening exercises are generally recommended for improving function in hypermobile joints. However there is no research that specifically looks at strengthening the muscles of the hand.
The general rule however applies: choose activities that can be adapted to give an adequate overload stimulus but at the same time allow the joints to be positioned so that they remain in non-hypermobile ranges.
Teach the child to use adapted grips for functional activities that do not place excessive stress on hypermobile joints.
Very little research has been done on splinting the hand in hypermobile subjects to improve function.
The Allied Health Professionals Group of the British Society for Paediatric and Adolescent Rheumatology make the following recommendation regarding splinting.
"Splinting is generally avoided due to the risk of deconditioning, but occasionally for the hypermobile MCP of the writing hand a splint is useful to prevent the hyperextension therefore aiding writing, reducing pain and fatigue."