Stretch injuries are among the most devastating forms of peripheral nerve injury; unfortunately, the scientific understanding of nerve biomechanics is widely and impressively conflicting. Experimental models are unique and disparate, victim to different testing conditions, and thus yield gulfs between conclusions. The details of the divergent reports on nerve biomechanics are essential for critical appraisal as we try to understand clinical stretch injuries in light of research evidence. These conflicts preclude broad conclusion, but they highlight a duality in thought on nerve stretch and, within the details, some agreement exists. To synthesize trends in nerve stretch understanding, the author describes the literature since its introduction in the 19th century. Research has paralleled clinical inquiry, so nerve research can be divided into epochs based largely on clinical or scientific technique. The first epoch revolves around therapeutic nerve stretching—a procedure known as neurectasy—in the late 19th century. The second epoch involves studies of nerves repaired under tension in the early 20th century, often the result of war. The third epoch occurs later in the 20th century and is notable for increasing scientific refinement and disagreement. A fourth epoch of research from the 21st century is just dawning. More than 150 years of research has demonstrated a stable and inherent duality: the terribly destructive impact of stretch injuries, as well as the therapeutic benefits from nerve stretching. Yet, despite significant study, the precise border between safe and damaging stretch remains an enigma.
Correspondence Mark A. Mahan: The University of Utah, Salt Lake City, UT. email@example.com.INCLUDE WHEN CITING Published online January 11, 2019; DOI: 10.3171/2018.8.JNS173181.Disclosures The author reports no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper.
HaraYNishiuraYOchiaiNSharulaNakajimaYKubotaS: New treatment for peripheral nerve defects: reconstruction of a 2 cm, monkey median nerve gap by direct lengthening of both nerve stumps. J Orthop Res30:153–1612012
HaraY, NishiuraY, OchiaiN, Sharula, NakajimaY, KubotaS, : New treatment for peripheral nerve defects: reconstruction of a 2 cm, monkey median nerve gap by direct lengthening of both nerve stumps. 30:153–161, 2012)| false
LundborgGRydevikB: Effects of stretching the tibial nerve of the rabbit. A preliminary study of the intraneural circulation and the barrier function of the perineurium. J Bone Joint Surg Br55:390–4011973
LundborgG, RydevikB: Effects of stretching the tibial nerve of the rabbit. A preliminary study of the intraneural circulation and the barrier function of the perineurium. 55:390–401, 1973)| false
PlattH: The Surgery of the Peripheral Nerve Injuries of Warfare: Being the Hunterian Lectures Delivered Before the Royal College of Surgeons of England on February 7th and 9th 1921. Bristol, England: John Wright & Sons1921
PlattH: . Bristol, England: John Wright & Sons, 1921)| false
WangYMaMTangQZhuLKoleiniMZouD: The effects of different tensile parameters for the neurodynamic mobilization technique on tricipital muscle wet weight and MuRf-1 expression in rabbits with sciatic nerve injury. J Neuroeng Rehabil12:382015
WangY, MaM, TangQ, ZhuL, KoleiniM, ZouD: The effects of different tensile parameters for the neurodynamic mobilization technique on tricipital muscle wet weight and MuRf-1 expression in rabbits with sciatic nerve injury. 12:38, 2015)| false