Balance in patients with anorexia and bulimia nervosa.

AIM: Neuro-muscular adaptations to the loss or increase in body weight may induce postural alterations. The aim of this study was to investigate the effect of body weight alterations on postural stability in patients with anorexia nervosa and bulimia. METHODS: The study enrolled 15 women affected by anorexia nervosa (AN), (mean body mass index [BMI] 15.8+/-1.8 kg/m(2)), 15 women affected by bulimia nervosa (BN), (mean BMI 20.1+/-2.9 kg/m(2)) and 11 healthy matched women (HC), (mean BMI 20.1+/-1 kg/m(2)). Two quiet standing conditions with eyes open (EO) and closed (EC) were analysed with an optoelectronic system (Vicon 460, Viconpeak, Oxford, UK) with passive markers to estimate the centre of mass (CoM) position. RESULTS: BN patients were more unstable than HC, showing statistically significant differences in antero-posterior CoM excursions and path length. AN patients showed non significant differences from HC. Only HC showed differences between EO and EC conditions, with significantly greater excursions in medio-lateral direction in EC condition (P<0.013) as well as an increased sway area (P<0.022). CONCLUSIONS: In BN, musculoskeletal factors seem to play a major role in the diminished postural control, which appear to be linked to body weight fluctuations rather than to BMI absolute values. No clear-cut postural instability was demonstrated in patients with AN as compared to HC. Visual input appears not to affect balance in patients with eating disorders. Possible further causes of postural instability in BN and implications for rehabilitation treatment are discussed.

Quantitative evaluation of functional limitation of upper limb movements in subjects affected by ataxia.

BACKGROUND AND PURPOSE: The design of useful and effective treatment strategies for movement disorders largely depends on the ability to objectively quantify changes in performances, providing reliable outcome measures. Evaluation of ataxia remains mainly assigned to different clinical scales, providing a semi-quantitative assessment. The aim of this study was to quantitatively characterize functional changes in upper limb movements in ataxic patients, using an optoelectronic system for objective measurements. METHODS: Fourteen patients with cerebellar ataxia and 27 healthy subjects were analyzed using an optoelectronic system with passive markers during pointing task and hand-to-mouth movement. Quantitative parameters capable of characterizing ataxic movements were defined using recorded kinematics. RESULTS: In both the considered functional movements, ataxic patients showed increased adjustment during the last phase of movement. The movement was less smooth than that in controls, with a fragmented trajectory presenting more direction changes than controls. CONCLUSIONS: The proposed protocol allows the quantitative characterization of the motion pattern of ataxic subjects in a non-invasive way. We believe that this analysis could represent a good tool for ataxia evaluation in a clinical context such as neurorehabilitation.

Kinematics of trunk movements: protocol design and application in obese females.

PURPOSE: Whether kinematic analysis of the trunk can provide useful clinical insight into the relationship between function and various spinal conditions is still under debate. The aim of this study was to develop a clinical protocol and an associated biomechanical model to characterize quantitatively the trunk movements in obese subjects. METHODS: Twenty (10 obese, 10 control) female subjects were evaluated with an optoelectronic system and passive markers attached to the spine during forward flexion, lateral bending, and rotation of the trunk. RESULTS: We found a systematic error due to skin artifacts of less than 5 degrees in both groups. Intra- and inter-subject standard deviation was less than 6 degrees . Obese subjects demonstrated a significantly reduced motion in the thoracic spine associated with an increased pelvic tilt angle as compared to controls. CONCLUSIONS: Our protocol was able to characterize trunk mobility in obese and normal subjects suggesting that kinematics could represent, even in an obese population, a promising method to investigate subclinical spinal disorders and to assess the effectiveness of rehabilitation programs.