Navigated transcranial magnetic stimulation of the primary somatosensory cortex evokes motor potentials in healthy humans’ flexor carpi radialis muscle - A pilot study

Background: Although previous studies targeted S1 by TMS to investigate its effect on the corticospinal pathway, there is no evidence if such stimuli produced by TMS would distinctly be restricted to it and not reach M1 interneurons adjacent to S1.Aim: We hypothesized that S1 vs. M1 stimulation-induced MEPs would be similar but smaller and less variable due to the focality of the magnetic pulse, considering that even if TMS is neuronavigated, the magnetic field is not selective enough and reaches M1 interneurons.Method: Healthy volunteers (n = 8, 2 females, age: 29.9 ± 5.49y) received single-pulse TMS over each hemisphere at each intensity of 90, 100, 110, and 120% of rMT in a randomized order. MEPs from the contralateral FCR were recorded.Results: We found no interhemispheric differences, but larger peak-to-peak amplitudes and variability of MEPs after M1 as compared to S1 stimulation. However, latency and waveforms of MEPs did not differ between S1 vs. M1 stimulation supporting the idea that TMS over S1 is not selective enough and can excite M1 interneurons thus producing MEPs on the contralateral FCR.Interpretation: Future studies should carefully consider these results when targeting S1 with TMS even if using a neuronavigation system.

Influence of a pre-shot dynamic stretching routine on free throw performance

Summary Study aim: The aim of the present study was to examine a single movement of dynamic stretching (SMDS) of the shooting arm as a pre-shot routine for free throw performance (FTP). Material and methods: The sample consisted of 60 junior and senior basketball players from the youth league of Bosnia and Herzegovina (B&H), and the national level – the First Division of B&H. The authors found that some players during a game and training sessions apply an SMDS of the shooting arm as a pre-shot routine for FTP. Since previous literature suggests that length of the routine and pre-performance behaviors are quite different among players of all levels, the sample was divided based on the number of training hours per week (lower/higher number of training hours) and basketball experience (experienced/less experienced). The procedure involves every player performing five free throws (FTs) without prior stretching, five FTs immediately after SMDS of the triceps muscle and five FTs after SMDS of the m. flexor carpi radialis. Results: After the first SMDS (m. triceps brachii) the percentage of FT slightly decreased in the first following attempt. After the second stretching (m. flexor carpi radialis), a significant FT percentage drop was noted in the first following FT for the whole sample. Players with more experience and more training hours per week had poorer results after the stretching. Conclusions: The SMDS routine did not enhance the FTP and it had a rather harmful effect on FTP, especially SMDS of the flexor carpi radialis muscle, and the authors do not recommend SMDS before the FTP.

TRANSFER OF NERVE BRANCHES OF THE FLEXOR CARPI RADIALIS TO THE POSTERIOR INTEROSSEOUS NERVE

ABSTRACT Objective: The objective of this paper was to study the anatomical variations of the flexor carpi radialis muscle (FCR) and determine in cadaver limbs whether the FCR nervous branch can be connected to the posterior interosseous nerve (PIN) without tension and how close to the target muscles the transfer can be performed. Method: Thirty cadaveric upper limbs were dissected. Results: The FCR received exclusive innervation of the median nerve, distally to the intercondylar line of the humerus. In 5 limbs, an isolated branch was found and in 25, a common trunk with other nervous branches occurred. We investigated whether the branch for the FCR was long enough to be transferred to the PIN. The diameter of the nerve branch for the FCR corresponded on average to 50% of the PIN. Conclusion: In 12 limbs, the branch destined to the FCR could be connected to the PIN, distally to the nerve branches to the supinator muscle even during the movements of the forearm and the elbow. In 18 specimens, it was necessary to mobilize the PIN for this innervation. Level of Evidence IV, Case Series.

Anomalous Medial Branch of Radial Artery: A Rare Variant

Radial artery is an important consistent vessel of the upper limb. It is a useful vascular access site for coronary procedures and its reliable anatomy has resulted in an elevation of radial forearm flaps for reconstructive surgeries of head and neck. Technical failures, in both the procedures, are mainly due to anatomical variations, such as radial loops, ectopic radial arteries or tortuosity in the vessel. We present a rare and a unique anomalous medial branch of the radial artery spiraling around the flexor carpi radialis muscle in the forearm with a high rising superficial palmar branch of radial artery. Developmentally it probably is a remanent of the normal pattern of capillary vessel maintenance and regression. Such a case is of importance for reconstructive surgeons and coronary interventionists, especially in view of its unique medial and deep course.