Determinants of sit-to-stand capability in the motor impaired elderly.

Among the healthy elderly, sit-to-stand (STS) movement largely depends on: (a) trunk bending momentum, (b) centre of gravity (CG) position before the body rises and (c) lower limb extensor muscle strength. Because determining whether (c) improvement would affect STS capability in the motor impaired elderly (MIE) has been recommended, we studied the relative importance of (a), (b) and (c) in determining a successful fast STS movement comparing the healthy elderly with MIE with orthopaedic disorders studied before and after a rehabilitation program. Force platform was used to measure body's posture and kinematics during a STS test and therefore to assess (a), (b) and maximum vertical velocity (VVpeak), assumed as outcome measurement. Knee extensor maximal isometric voluntary contraction normalized by body mass (nMVC) was an indicator of (c). A multiple regression model was built to predict VVpeak from the three determinants of STS movement. In both groups, the model significantly determined VVpeak, with (a) and (c) being significant predictors of VVpeak and (a) being the major predictor. Rehabilitation was effective in improving nMVC. This process resulted in a change of the relative importance of (a) and (c), strength becoming the major predictor of VVpeak. In conclusion the present study demonstrates that a rehabilitative intervention aimed at increasing strength is effective in improving STS capability in MIE.

Cost of walking and locomotor impairment.

The aim of the present study was to evaluate the importance and the necessity of metabolic measurements to quantify locomotor impairment in a clinical context. Oxygen consumption, heart rate, pulmonary ventilation and walking speed were measured during locomotion in 14 normal subjects, used as a control group, and 82 patients with different pathologies [hemiparetic, paraparetic, tetraparetic, orthopaedic and paraplegic patients, who walked using a reciprocating gait orthosis (RGO)]. The subjects were characterized on the basis of a cumulative impairment score (CIS), based on clinical scales commonly used to evaluate impairment and disability in locomotion. Appropriate indices of energy, cardiac and ventilatory costs expressed per metre walked, globally called physiological costs, were obtained. It resulted that the most comfortable speed (MCS) of normal subjects was significantly higher than that of each group of patients. Normal subjects' physiological costs were found to be significantly lower than those of patients who needed either a device or the help of a person to walk. All measured parameters correlated significantly with each other. The MCS was found to be the most correlated parameter with the CIS (r = 0.8), and therefore it must be considered the best single measurement, if only one is to be used. Measurements more precise than MCS, such as the physiological costs, may be necessary in clinical trials.

The cardiovascular work of competitive dinghy sailing.

BACKGROUND: Hiking is the special manoeuvre, which the dinghy sailor uses to counterbalance the capsizing effect of the wind on the boat. In the present research the work required of the heart by this exercise was studied in the laboratory using a boat simulator. METHODS: Seven Laser male sailors selected from those in the first places in the junior national rank participated in this study. Their endurance, at different levels of isometric hiking efforts, was measured. Energy expenditure due to hiking was estimated from measurements of oxygen consumption, carbon dioxide elimination and blood lactate concentration. The cardiac load was evaluated by measuring blood pressure using the conventional method and heart rate measured by electrocardiography. Cardiac output was measured using the CO2 re-breathing method. Left ventricular work was then calculated as cardiac output multiplied by mean arterial pressure. RESULTS: The most relevant result was that, while whole body cost of hiking was relatively low (about 1 IO2 min-1), the power of the heart was very significant: cardiac output almost doubled with respect to that at rest and arterial mean pressure rose from 12.5 kPa (rest) to 18.5 kPa (hiking). Thus, left ventricular power rose from 1.2 Watt to 3.2 Watt, which is a typical cardiovascular response to muscular isometric contraction. CONCLUSIONS: These results assume relevance when a person's eligibility for sailing sports is evaluated.

Is the Olympic boardsailor an endurance athlete?

The present study was carried out in order to describe the physiological profile of top Olympic boa rdsailors of both genders and to measure the energy cost during actual boardsailing with particular attention to the most demanding conditions. Fourteen elite Olympic boardsailors (7 males and 7 females) volunteered to participate in the study. Each subject underwent a maximal cycle ergometer test in orderto measure VO2peak and ventilatory threshold (Tvent). Additionally, anthropometric measurements including body fat percentage were taken. The cardiorespiratory demand and the energy cost of actual boardsailing were assessed by means of a very light telemetric device (K2 Cosmed) which allowed the measurements of VO2, VE and HR. VO2peak was 63.6 +/- 2.3 ml x kg(-1) x min(-1) (Tvent 70% of maximum) and 49.2 +/- 4.1 (Tvent 60% of maximum) in males and females, respectively. The data recorded during actual boardsailing show that this sport activity can be classified as aerobic, the VO2 values being above or very close to those of Tvent values (75% and 60% of the maximum in males and females). Furthermore the mean blood lactate values obtained at the end of each regatta testing were 6 +/- 2 mMol x l(-1) in males and 5 +/- 1.5 mMol x l(-1) in females indicating a partial involvement of anaerobic metabolism, which in some regatta phases could represent a limiting factor for performance.

The physiological demands of sail pumping in Olympic level windsurfers.

This study investigated the physiological effects of sail pumping (PB)--a manoeuvre often adopted to provide additional propulsion to the board--in Olympic Class Windsurfing, following relaxation of the "no-pumping" rules by the International Federation. Fifteen Olympic-level windsurfers (10 men) from nine different countries volunteered for the study, which was performed during two international Olympic regattas. The measurements were carried out during actual sailing when both PB and not-pumping (NPB) using a portable metabolimeter. Windsurfing, when PB, elicited a dramatic increase in cardiorespiratory responses compared to NPB. Mean (SD) values for oxygen uptake and heart rate during NPB for the men and women were: 19.2 (4.4) and 15.7 (3.3) ml x kg(-1) x min(-1), and 110 (10) and 122 (12) beats x min(-1), respectively, whereas the values in PB were: 48.4 (5.7) and 40.2 (4.2) ml x kg(-1) x min(-1), and 165 (12) and 172 (13) beats x min(-1), respectively. All the PB parameters, with the exception of heart rate (HR), were significantly higher in the men than in the women but no differences were observed between the sexes in NPB with the exception of HR, which was higher in the women. Our results suggest sail pumping is as physically demanding as most aerobic sporting activities. In the context of the need to deal with a highly demanding athletic branch of sailing as part of an Olympic regatta, recommendations are made on how best to make physical and dietary preparations.

Daily hunger sensation and body composition: I. Their relationships in clinically healthy subjects.

The human hunger sensation (HS) is a perceptive signal characterized by day-night variability (DNV). This pattern was investigated with respect to its relations with the body compartments in 22 clinically healthy subjects (CHS, 11 males and 11 females, mean age: 24 +/- 2.5 years, mean BMI: 21 +/- 1.7). The DNV was investigated by means of conventional descriptive statistics and the single cosinor method (SCM). Both procedures were applied to the orexigram, i.e., the 24-h profile of the orectic stimulus (OS) provided by each subject, who self-rated his/her HS (from 1 to 10 hunger units) every half hour. Body composition was investigated by Bioelectrical Impedance Analysis (BIA) on the day when the orexigrams were compiled. It was found that the daily HS level correlates positively with the Free Fat Body Mass (FFBM) and negatively with the Fat Body Mass (FBM). These opposite relations indicate that HS is stimulated by the needs of the FFBM, and inhibited by expansion of the FBM, and provide further evidence of the existence of an "adipostat" anorectic mechanism.

Anxiety, depression, hunger and body composition: III. Their relationships in obese patients.

The present paper explores the relationships between anxiety, depression, hunger sensation and body composition in obese patients (OP). The aim is to detect whether or not there are abnormalities in these relationships in OP as compared to clinically healthy subjects (CHS). The study was performed on 22 CHS (2 M, 20 W; mean age = 24 +/- 2 years; mean body mass index = 21 +/- 2 kg/m2) and 48 OP (4 M, 44 W; mean age = 40 +/- 17 years; mean body mass index = 32 +/- 7 kg/m2). Anxiety and depression were found to be correlated, negatively, with the relative lean body mass, and, positively, with the fat body mass in OP but not in CHS. These findings corroborate the idea that anxiety and depression can reach an abnormal expression when obesity shows its worst loss in lean body mass and its highest expansion in adipocyte mass. As hunger sensation was found not to correlate with either anxiety or depression in OP, the opinion is expressed that the impairment of anxio-depressive integrity is a corollary of obesity rather than a primary affective disorder leading to obesity via an enhanced food intake.

Daily hunger sensation and body compartments: II. Their relationships in obese patients.

Hunger sensation (HS) is a signal whose levels change during the 24-h day. The daily mean level of HS was correlated with the human body compartments, as investigated by bioelectrical impedance analysis, to detect the relationship between the orectic perception and both the free fat mass (FFM) and the fat body mass (FBM) in 22 clinically healthy subjects (CHS) (2 M, 20 W, BMI: 18.5-24.0 kg/m2) and 48 obese patients (OP) (4 M, 44 W, BMI: 25.2-54.7 kg/m2). In CHS, the daily mean level of HS correlated positively with the FFM and negatively with the FBM. These correlations were not present in OP. This lack of relationships between HS and the body compartments where energy is maximally consumed (i.e., the FFM) and maximally stored (i.e., the FBM) indicates that the orectic response to energy expenditure and the orectic inhibition to fat accumulation are feedback mechanisms which are impaired in obesity.