Remobilization through stretching improves gait recovery in the rat.

Remobilization of a previously immobilized rat right hindlimb in the ankle plantar-flexion-shortened position by free movement alone or associated with intermittent passive stretching was assessed by analysis of gait variables and dorsiflexion range of motion. The variables were related with the expression of extracellular matrix proteins and the addition of serial sarcomeres. Sixty-four female Wistar rats were divided into 8 groups: immobilized, free for 10 days, immobilized/stretched/free for 1, 3 or 10 days, immobilized/free for 1, 3 or 10 days.

High voltage pulsed current stimulation of the sciatic nerve in rats: analysis by the SFI.

Objective: To analyze the efficiency of high voltage pulsed current (HVPC) with early application in three different sites, in the regeneration of the sciatic nerve in rats submitted to crush injury, the sciatic functional index (SFI) was used to assess the functional recovery.

Methods: After crushing of the nerve, 57 animals were submitted to cathodal HVPC at frequency of 50Hz and voltage of 100V, 20 minutes per day, 5 days per week. The rats were divided into five groups: control group; ganglion group; ganglion + muscle group; muscle group; and sham group.

BIOMECHANICAL AND HISTOLOGICAL ANALYSIS OF THE GASTROCNEMIUS IN RATS SUBJECTED TO MUSCLE INJURY AND TREATMENT WITH LOW-LEVEL LASER THERAPY.

Objective: To mechanically and histologically evaluate the application of low-level laser therapy to the reparative process on lesions caused by impact on the gastrocnemius muscles of rats.

Methods: 45 female Wistar rats were divided into three groups (n=15/ group): C (control, no lesion), ML (muscle lesion) and ML-L (muscle lesion and laser therapy). The experimental muscle lesion was produced by letting a 250 g load drop from a height of 30 cm, directly onto the muscle.

A new treadmill-type motorized walking belt machine for video recording of the rat's gait and sciatic functional index measurement. A comparative study with other methods.

The sciatic functional index (SFI) is a remarkable tool to assess dysfunction and functional recovery of the sciatic nerve of rats. Usually measured on hind foot imprints on paper, a new method is now being proposed, by direct analysis of video recorded foot sole images obtained with a treadmill-type walking belt machine functioning with gait speed control (G1). Results were compared with the SFI measured on imprints on paper (G2) and on video recorded foot sole images obtained with a static see-through runway (G3).

Is the Sciatic Functional Index always reliable and reproducible?

The Sciatic Functional Index (SFI) is a quite useful tool for the evaluation of functional recovery of the sciatic nerve of rats in a number of experimental injuries and treatments. Although it is an objective method, it depends on the examiner's ability to adequately recognize and mark the previously established footprint key points, which is an entirely subjective step, thus potentially interfering with the calculations according to the mathematical formulae proposed by different authors. Thus, an interpersonal evaluation of the reproducibility of an SFI computer-aided method was carried out here to study data variability.

Can therapeutic ultrasound influence the regeneration of peripheral nerves?

An experimental study of the influence of the therapeutic ultrasound on the regeneration of the sciatic nerve submitted to a controlled crush injury was carried out in rats. Twenty female Wistar rats weighing 250 g on average were used and divided into two groups of 10 animals each, respectively, submitted to: (1) crush injury followed by ultrasound irradiation and (2) crush injury only. Under general anaesthesia the sciatic nerve was exposed on the right thigh and crushed with a device especially developed and built for this purpose, with a 15,000g constant load for 10 min, affecting a 5mm-long segment of the nerve proximal to its bifurcation.