Validation of the range of dry needling with the fascial winding technique in the carpal tunnel using ultrasound.

OBJECTIVES: To use ultrasound imaging to show how the needles in dry needling applied in the carpal tunnel can reach the transverse carpal ligament, acting on it in the form of traction-stretching when the fascial winding technique is performed. The potential associated risks are also assessed.

DESIGN: Validation study.

PARTICIPANTS: Healthy volunteers (n = 18).

METHODS: Four dry needling needles were applied to the carpal tunnel, only using anatomical references, according to the original approach known as "four-pole carpal dry needling", and manipulating the needles following the so-called fascial winding technique according to the authors, in the form of unidirectional rotation. An ultrasound recording of the distance reached was then performed, and compared with the mechanical action achieved on the transverse carpal ligament.

RESULTS: 93.1% of the needles placed came into contact with the transverse carpal ligament with traction-stretching of the ligament observed when the needles were manipulated with the fascial winding technique in 80.6%. The mean distance from the tip of the needle to the median nerve was 3.75 mm, with CI95% [3.10, 4.41] and it was 7.78 mm with CI95% [6.64, 8.91] to the ulnar artery. Pain immediately after the technique concluded was of mild intensity, almost nil 10 min later, and non-existent after one week.

CONCLUSION: Dry needling with fascial winding technique in the carpal tunnel using the four-pole carpal dry needling approach is valid for reaching and traction of the transverse carpal ligament, and may stretch it and relax it. It is also safe with regard to the median nerve and ulnar artery, with a very mild level of pain.