Critical load of the human cervical spine: an in vitro experimental study

Neck motion, motor control, pain and disability: A longitudinal study of associations in neck pain patients in physiotherapy treatment

“…The complexity of these relationships is further illuminated by the biomechanics and anatomy of the head and neck plant, also keeping in mind the influence of psychological factors. The head is, in contrast to the lumbar spine, an unstable system with a relatively small base of support where the muscles contribute to approximately 80 % of the stability of the cervical spine (Panjabi et al, 1998). The large number of muscles in the cervical region, whereby approximately 20 pairs of muscles contribute to head movement (Kamibayashi and Richmond, 1998), indicate that a specific head movement can be accomplished by several different motor commands or muscle activation patterns .…”

Cervical disc prosthesis versus arthrodesis using one-level, hybrid and two-level constructs: an in vitro investigation

“…As recommended by Panjabi et al [28][29][30], to analyse and understand changes in kinematics and IDP at adjacent levels, we used the concept of displacement-control protocol to compare intact and instrumented spines (i.e. equivalent to hybrid testing protocol).…”

“…There are still controversies using load-controlled versus displacement-controlled protocol during experimental testing [28,[39][40][41]. Using pure moments loading, as in our experimental protocol, for all the testing conditions, one ensured that the load magnitude does not vary along the spinal segment and between the testing conditions.…”

“…As an example, we did not find any significant difference at 2 N m between 2-level TDR and 2-level arthrodesis for the three loading conditions. On the other hand, applying the same angular displacement to the different testing conditions (based on intact ROM), as proposed by Panjabi et al [28,29] (hybrid protocol) exposes to the risk of excessive loads and disco-ligamentar injuries for the stiffest constructs, especially for multilevel arthrodesis construct. Hence, in our study, we used loadcontrolled protocol for biomechanical tests whereas we applied the concept of displacement-control protocol to compare the biomechanical behaviour of adjacent levels between the different testing conditions.…”

“…In 2010, Cunningham et al [24] conducted an In vitro human cadaveric study comparing the ROM of eight cervical spines tested in six different conditions: intact, 1-level TDR, 1-level ACA, hybrid, 2-level TDR and 2-level ACA. They used hybrid testing protocol described by Panjabi et al [28,29]. No IDP was registered during biomechanical tests.…”