Proprioception and isometric muscular strength in haemophilic subjects

Haemophilia is characterized by intra-articular bleeding, often requiring immobilization, which may result in muscle atrophy and impaired proprioception. The aim of the study was to investigate differences in proprioceptive performance and isometric muscular strength of the lower limbs in haemophilic subjects compared with control subjects. Twelve subjects with severe haemophilia (11 haemophilia A; one haemophilia B) vs. 12 control subjects were matched for anthropometric data and tested for differences of proprioception (one-leg-stand, posturomed, angle-reproduction, and tuning fork tests) and isometric strength (leg press, knee extensor). The static proprioceptive performance of the haemophilic group, as measured by the one-leg-stand test (on hard or soft ground, with open or closed eyes; P < 0.05) was demonstrably impaired (by 41-363%). In contrast, the dynamic proprioceptive performance measured by the posturomed test did not show any difference between the groups. The local proprioceptive performance (angle-reproduction test) of the knee, (the most commonly affected joint in haemophiliacs) showed a trend to impaired function but was not distinctly different from that of controls. The quantitative sensory function (tuning fork) showed significant (P < 0.05) impairment of 9-10% in the haemophilic subjects. Additionally, the isometric muscular strength of the leg extensor was weaker (32-38%) in the haemophilic group when the limbs were tested individually as well as bilaterally (P < 0.05). In conclusion, the results suggest that global proprioceptive performance is impaired and that the isometric strength of the leg extensors is weaker in the haemophilic subjects. Therefore, specialized training for global proprioception would be helpful in order to compensate for proprioceptive deficits. This exercise regimen should also include safe strength-training for an optimal stabilization of the joints, but must be adapted to the individual needs and situations of the haemophilic subjects.