I just received another referral for a kid with “weak’ hands. Can’t hold a pencil correctly, can’t make a dark enough mark on paper when he writes or colors. But his mom says he has quite a grip on an object when he doesn’t want to hand something over. He plays soccer without problems and otherwise functions well in a regular classroom. Could it be that hypermobility is his real problem?
Some children display problems with fine motor skills due to low muscle tone alone. Many times, their low tone is significant enough to create poor joint alignment and stability, resulting in joint hypermobility as well as low muscle tone. But kids can have joint laxity with typical muscle tone. Assessing the difference between tone, strength, alignment and endurance is why you get an evaluation from a skilled therapist. And even then, it can be tricky to determine etiology with the youngest children because they cannot follow directions or answer questions. Time to take out your detective hat and drill down into patient history and do a full assessment.
With older kids, both low tone and joint laxity can lead them over time to develop joint deformity. Like a tire that you never rotated, inappropriate wear and tear can create joint, ligament and tendon problems that result in worse alignment, less stability and endurance, and even pain. And yes, weakness is often observed or reported, but it often is dependent on posture and task demands, rather than being consistent.
What does the classic hypermobile hand look like? Here are some common presentations:
- The small joints of the fingers and thumb look “swaybacked”, as the joint capsule is unstable and the tendons of the hand exert their pull without correct ligament support.
- The arches of the hand aren’t supported, so the palm looks flat at rest and during grasp. By late preschool, the arches of the hand should be evident in both states.
- The fleshy bases of the thumb and pinky ( for all you therapists, the thenar and hypothenar eminences) aren’t pronounced, due to the lack of support reducing muscle development during daily use.
- Grasp and pinch patterns are immature and/or atypical. A preschooler uses a fisted grasp to scribble, a grade-school child uses two hands to hold an object that should be held by one hand and a “hook” grasp on a pencil.
- Grasp and pinch may start out looking great, and deteriorate with the need for force. Or prehension begins looking poor and improves for a while, until fatigue sets in.
Don’t forget that hypermobility creates poor sensory processing feedback loops. Reduced proprioception and kinesthesia will result in issues grading force and controlling movement without compensation such as visual attention and decreased speed.
For ideas to address the difficulties children face when they have hypermobility in their hands, take a look at For Kids With Sensory and Motor Issues, Add Resistance Instead of Hand-Over-Hand Assistance and Does An Atypical Pencil Grasp Damage Joints or Support Function In Kids With Hypermobility?. Depending on the age and skill level of the child, adaptations and education can be just as important as therapeutic exercise.