Spine range of motion

Hi,

I see in the repository models that the spine is only mobile in its lumbar and cervical sections. Is that realistic ?

Thank you.

Pierre

Hi Pierre,

No, it is a limitation, however, for many physical activities not critical such as gait. The ribcage is a tricky component to model - keep in mind breathing, elastic deformations of the ribs and so on. But also the range of motion is somewhat limited due to the cartilaginous and muscular interconnection between ribs and the spinal column in thoracic region. Activities with axial rotation too large degrees are probably the ones to avoid.

Some of our users model the thoracic spine themselves: “Influence Of Kyphosis On Spinal Loading”, G. Spreiter et al., CMBBE 2012. We also have an implementation of the thoracic spine, but we cannot conclude that it is reliable and, therefore, do not include this experimental version into the repository.

Best regards,
Pavel

Hi Pavel,

OK thank you. I just wanted to know if it was a current limitation.I also want to know what are the following ratios of the “SRMatrixes.any” present in the SpineRhythmDrv.

Coef = {
{-1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 7.105616e-002, 0, 0},
{0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
{0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 7.105616e-002},

{0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2.276759e-001, 0, 0},
{0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1.421123e-001, 0},
{0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2.276759e-001},

{0, 0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4.020500e-001, 0, 0},
{0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3.132395e-001, 0},
{0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4.020500e-001},

{0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 5.784718e-001, 0, 0},
{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 4.908604e-001, 0},
{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 5.784718e-001},

{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 7.462112e-001, 0, 0},
{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 6.660833e-001, 0},
{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 7.462112e-001},

{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 9.131695e-001, 0, 0},
{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 8.263391e-001, 0},
{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 9.131695e-001}};

// Constant vector

Const = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};

Thank you.

Pierre

Pierre,

these ratios are used to distribute thoracopelvic angle to the individual joint angles of the lumbar spine.

Regards,
Pavel