Effect of electrode location on EMG signal envelope in leg muscles during gait.

The aim of the study was to assess the variability of EMG signal envelope with electrode location during gait. Surface EMG signals were recorded from 10 healthy subjects from the tibialis anterior (TA), peroneus longus (PL), gastrocnemius medialis (GM), gastrocnemius lateralis (GL), and soleus (SO) muscles. From TA, PL, GL and GM, signals were acquired using a two-dimensional grid of 4 x 3 electrodes (10 x 15 mm in size, as used in most gait laboratories) with 20-mm interelectrode distance in both directions. A similar grid of 3 x 3 electrodes was used for SO. EMG envelope was characterized by its peak value, area after normalization by the peak value, and time instant corresponding to the maximum. The maximum relative change in peak value with electrode location, expressed as a percentage of the peak value in the central location, was (mean+/-SD) 31+/-18% for TA, 29+/-13% for PL, 25+/-15% for GL, 14+/-8% for GM, and 26+/-14% for SO. The maximum relative change in area was 29+/-13% for TA, 73+/-40% for PL, 31+/-23% for GL, 35+/-20% for GM, 20+/-13% for SO, and in the position of maximum, computed as distance from the maximum position in the central channel, it was 5+/-10% of the gait cycle for TA, 26+/-16% for PL, 3+/-2% for GL, 3+/-1% for GM, 3+/-3% for SO. A crosstalk index, defined on the basis of the expected intervals of muscle activation for healthy subjects, indicated that estimated crosstalk was present between TA and PL, in an amount which depended on electrode location. It was concluded that the estimate of muscle activation intensity during gait from surface EMG is variable with location of the electrodes while timing of muscle activity is more robust to electrode displacement and can be reliably extracted in those cases in which crosstalk is limited. These results are valid for healthy subjects, where the level of muscular activity during gait is much lower than maximum.

[Experience in prevention of risks caused by manual movement of patients in a health institution]. / Un'esperienza di contenimento del rischio da movimentazione manuale di pazienti in un'azienda sanitaria.

In its hospitals, the local Reggio Emilia Division of the National Health Service has introduced beds and stretchers with up-and-down movement systems, electrical lifters for patients, and highly mobile trained more than one thousand workers in the correct execution of maneuvers for moving patients manually platforms and litters for transferring patients from stretcher to bed. The Division has also. The risk evaluation models available in the literature have proved to be inadequate for instituting a program of improving service or for adequately supporting the doctor in charge. To overcome these limitations, a standard of risk evaluation called SpoSo ("Spostamenti Sollevamenti"--"Moving and Lifting") has been experimentally adopted.

[Intertrochanteric osteotomy of the hip. Retrospective (10-18 years) clinical and radiologic study of 30 interventions]. / Osteotomia intertrocanterica dell'anca. Revisione clinica e radiologica a distanza (10-18 anni) di 30 interventi.

The authors report on 28 patients with degenerative arthritis of the hip who underwent intertrochanteric osteotomy of the femur between 1970 and 1978. Two subjects were operated on bilaterally, bringing the total number of hips to 30. The follow-up period averaged 11.8 years. All patients underwent thorough clinical and radiographic examination as well as basography and computed electrogoniometry. The basographic examination consists of analysis of the temporal phases of gait, revealing angular abnormalities of the various joint components of the lower limbs which occur during walking. Processing the data by computer shows any anomaly present in the lower limbs. The results of treatment were good for the most part, and thorough functional examination by computer often revealed a poor radiographic result corresponding to a better clinical result.