Therapeutic ultrasound in physical medicine and rehabilitation: characterization and assessment of its physical effects on joint-mimicking phantoms.

The aim of the study described here was to quantitatively assess thermal and mechanical effects of therapeutic ultrasound (US) by sonicating a joint-mimicking phantom, made of muscle-equivalent material, using clinical US equipment. The phantom contains two bone disks simulating a deep joint (treated at 1 MHz) and a superficial joint (3 MHz). Thermal probes were inserted in fixed positions. To test the mechanical (cavitational) effects, we used a latex balloon filled with oxygen-loaded nanobubbles; the dimensions of the oxygen-loaded nanobubbles were determined before and after sonication. Significant increases in temperature (up to 17°C) with fixed field using continuous waves were detected both in front of and behind the bones, depending on the US mode (continuous wave vs. pulsed wave) and on the treatment modality (fixed vs. massage). We found no significant differences in mechanical effects. Although limited by the in vitro design (no blood perfusion, no metabolic compensation), the results can be used to guide operators in their choice of the best US treatment modality for a specific joint.

Evaluation of Staff's Job Satisfaction in the Spinal Cord Unit in Italy.

In July 2007 a Spinal Cord Unit was set up in Turin (Italy) within the newly integrated structure of the Orthopaedic Traumatologic Centre, warranting a multidisciplinary and professional approach according to International Guidelines. This approach will be possible through experimentation of a personalized care model. To analyze job satisfaction of health care professionals operating within the Spinal Cord Unit, preliminary to organizational change. Data collection was carried out by using questionnaires, interviews, shadowing. Results from quantitative analysis on the self-filled questionnaires were integrated with results from qualitative analysis. All the health care professionals operating in the field were involved. Positive aspects were the perception of carrying out a useful job, the feeling of personal fulfilment and the wish to engage new energies and resources. Problematic aspects included role conflict among staff categories and communication with managers. The positive aspects can be exploited to create professional practices facilitating role and expertise integration, information spreading and staff identification within the organization rather than team work. Data of job satisfaction and self efficacy of health care workers can be considered basic requirement before implementing an organizational change. The main challenges is multiprofessional collaboration.

Electrical manifestations of muscle fatigue during concentric and eccentric isokinetic knee flexion-extension movements.

The quantification of the progression of muscle fatigue during a sustained contraction is a valuable tool in several clinical applications, ranging from the evaluation of functional impairment to the development of specific rehabilitative and training protocols. In these fields, great importance is given to isokinetic contractions. The aim of this paper was twofold: first, to propose signal processing methods for assessing the spectral changes of the surface myoelectric signal due to fatigue during isokinetic concentric and eccentric knee flexion-extension movements at a given angular velocity (60 degrees/s); second, to analyze the electrical manifestations of muscle fatigue of four thigh muscles (vastus lateralis, vastus medialis, rectus femoris, and biceps femoris) in the two contraction modalities (i.e. concentric versus eccentric). We demonstrated that, when considering concentric contractions, localized muscle fatigue can be assessed by computing the mean frequency of the frequency marginal of the time-frequency distribution derived from the surface myoelectric signal collected during each contraction cycle. Stronger nonstationarities were observed in the surface myoelectric data recorded within each cyclical movement of the studied eccentric exercise. Thus we propose the computation of the instantaneous mean frequency of the signal based on an original cross-time-frequency algorithm, which proved more sensitive than the frequency marginal in tracking the spectral changes associated with localized muscle fatigue. We derived the average fatigue pattern of the investigated muscles from experimental data recorded from a sample population consisting of twenty healthy subjects and we statistically compared the two contraction modalities. Our results showed that the electrical manifestations of muscle fatigue during concentric contractions were higher than those found during eccentric contractions, although in the latter modality the torque exerted and the mechanical work produced by the subjects were larger than those recorded during the concentric exercise. The results presented in this paper have potential clinical application and they could play an important future role in investigations of muscle behavior during dynamic, highly fatiguing contractions.