Strain in the Tibial and Plantar Nerves with Foot and Ankle Movements and the Influence of Adjacent Joint Positions

Abstract

We studied the influence of different positions in neighboring joints on strain in the tibial and plantar nerves during ankle and toe movements. Tibial nerve strain at the ankle was measured during ankle dorsiflexion in ten cadavers; plantar nerve strain was measured during toe extension. Tibial nerve strain increased with ankle dorsiflexion (mean increase: 3.9%) and strain was higher when the nervous system was pretensioned by either knee extension or hip flexion (p ≤ .011). Strain was even higher when the nerve bed was elongated at both the hip and knee (p ≤ .006) before performing dorsiflexion. A similar trend was observed for the plantar nerves with ankle positioning. In conclusion, the change in nerve strain is strongly influenced by positions in neighboring joints. This insight into nerve biomechanics provides a foundation for progressive mobilization exercises for disorders such as tarsal tunnel syndrome.

The effects of neurodynamic mobilization on fluid dispersion within the tibial nerve at the ankle: an unembalmed cadaveric study

“…Finally, limb position is an important consideration in the clinical use of neurodynamic mobilization as there is a mutual relationship between joint position and the amount of strain and excursion. 29,34,60,61 Therefore, additional studies investigating various limb positions on fluid dispersion are warranted. Limitations of this current study include the inability to generalize the findings to live subjects due to active physiological processes, the inability to completely generalize the results to other peripheral nerves or nerve roots, and the inability to generalize the findings to nerves exhibiting a loss of elasticity due to fibrosis or adhesions, 46,63 which may alter the manner in which fluid is dispersed.…”

“…29,30,34,[60][61][62] While these studies provide valuable information regarding peripheral nerve movement and strain, they provide no insight into the mechanisms responsible for the benefits of using neurodynamic mobilization. Furthermore, no studies were found that address the effects of neurodynamic mobilization on nerves exhibiting pathophysiological responses such as impaired nerve conduction, ischemia, inhibited axonal transport, or intraneural edema.…”

“…15,[23][24][25][26][27][28] Impaired nerve mobility and increased mechanosensitivity provide the basis for existing studies of neurodynamic techniques. These studies examined neurodynamic techniques with respect to quantification of strain 29 and excursion, [30][31][32][33][34][35][36][37] as well as symptom reproduction. 8,34 Impaired nerve mobility and mechanosensitivity can be clinically assessed by measuring changes in joint range of motion, 38,39 pain reproduction, 4,8,10,[40][41][42] or change of symptoms following neurodynamic mobilization.…”

“…51,52 Neurodynamic mobilization techniques are often used clinically for restoring nerve mobility 39 and decreasing pain. 43,53,54 In the lower extremity, neurodynamic techniques incorporate ankle range of motion for neurodynamic testing 2,4,29,40,41,55,56 and treatment. 57 Moreover, repetitive ankle motion (e.g.…”

Impact of Movement Sequencing on Sciatic and Tibial Nerve Strain and Excursion During the Straight Leg Raise Test in Embalmed Cadavers

“…Consistent with other studies, the calcaneal tendon was cut to obtain adequate ankle dorsiflexion. 1,2,8 The exact effect of transecting the calcaneal tendon on tibial nerve biomechanics is unknown but would most likely have had a comparable effect for the different sequences. The DVRT strain gauge was inserted into the nerve with 2 barbed pins separated by approximately 3 cm.…”