Deterioration of balance control after limb-saving surgery.

Abstract

Evaluation of the changes in balance control observed in patients after limb-saving surgery for malignant tumors of the lower limb. Case series. In 11 patients who underwent limb-saving surgery and 10 healthy, age-matched controls, displacement of the amplitude of the center of pressure (ACP) and velocity of the center of pressure (VCP) during normal standing and standing on a balance board were registered. Adding such constraints as standing with eyes closed and performing a Stroop task made standing more complex. During normal standing and on the balance board, both groups showed comparable ACP and VCP values. With eyes closed, both patients and controls showed a higher amplitude and velocity in the anterior-posterior direction. In the patient group, the Stroop task affected the ACP (4.5 +/- 0.8 mm) compared with normal standing (2.9 +/- 0.4 mm) and VCP (18.6 +/- 3.0 mm/sec) compared with normal standing (11.9 +/- 1.0 mm/sec). During balance board standing, the authors found a difference in the VCP for both groups whose eyes were closed and who performed under dual-task conditions (controls, 23.2 +/- 3.3 and 14.9 +/- 2.9 mm/sec; patients, 80.1 +/- 12.9 and 23.6 +/- 3.4 mm/sec). Although the patient group showed impressive upright standing after limb-saving surgery, upright standing become more difficult under higher visual and cognitive loads. This finding indicates that the level of postural automatism is not complete in these patients.