Muscular force is reduced in neurofibromatosis type 1

To measure muscular force in neurofibromatosis type 1 (NF1) patients.

The maximal voluntary muscular force (F(max)) was measured in the first 21 volunteer patients without acute health problems at the routine annual examination in the Neurofibromatosis Outpatient Reference Center during October-November (2007). The NF1 individuals were 9 males and 12 females, aged from 7 to 60 years and physically sedentary. The healthy control group was 21 healthy subjects matched to NF1 group by age, sex and physical activity. A handgrip test instrument was used to measure maximal force. To allow comparisons between physically different patients, forearm circumference (cm) was measured with a tape and forearm cross sectional area was derived to express the force per unit of forearm area. Data were compared using a t Student test (P<0.05).

The mean F(max) of NF1 male (260-/+136 N) and NF1 female (217-/+76 N) were lower than expected for their sex and age. Healthy men showed greater F(area) (9.8-/+3.2 N x cm(-2)) than NF1 men (5.7-/+2.6 N x cm(-2)) and healthy women (6.7-/+1.6 N x cm(-2)) showed greater F(area) than NF1 females (5.7-/+1.9 N x cm(-2)).

Maximal voluntary muscle force was reduced in NF1 patients.