Background: Abundant literature exists on the morphology of the carpal tunnel. Despite this, the shape of the carpal tunnel has been reported erratically, and most studies did not attempt to correlate findings with measurements taken from cadavers. The objective of this study was to perform a morphological analysis, determine the shape and mean dimensions of the carpal tunnel, determine the level of the narrowest area of the tunnel, and establish a set of values capable of serving as a reference for carpal tunnel release. Methods: The carpal tunnels of 20 fresh cadaveric hands were dissected, and acrylic casts were created and measured using industrial computed tomography. Results: Of the 20 casts, 19 were shaped like elliptic cylinders, with little variation in their measurements along the length. The location of the narrowest section of the carpal tunnel is very different among casts, and the length of the roof of the carpal tunnel ranged from 21.26 to 29.86 mm. Conclusions: The most common shape of the carpal tunnel is an elliptic cylinder. Because of the unpredictability of the location of the narrowest area of the carpal tunnel, carpal tunnel release must continue through all extension of its roof. We advise that the release should rarely be extended distally more than 30 mm from the distal palmar wrist crease, which corresponds, in most cases, to the middle of the pisiform.

Feedforward is an educational strategy in which a professor gives orientations to students, prior to a certain task or assessment, in order to show them how to perform well in that upcoming task. This chapter explores the contribution of screencasts as one possible solution to providing feedforward. A screencast is a digital recording of computer screen output, including audio voiceover. If well planned and recorded, screencasts can expose students to the common errors in a certain field, as well as to the best practices that avoid or correct those mistakes. This chapter tests the following hypothesis: students who were exposed to feedforward with screencasts (experimental group) had better grades than those who did not see these common mistakes screencasts (control group). The students were Portuguese undergraduates of physiotherapy, taking a course of Inferential Statistics. The results show that the 48 students in the experimental group achieved an average of 11.64 (in a scale of 0 to 20), significantly higher than the average of 9.96 of the 41 students in the control group.