Outcome
Type |
Measure |
Description |
Time frame |
Safety issue |
Primary |
Change in DP ARF marginal peak displacement |
Marginal peak displacement (MPD) is a metric developed to qualitatively describe the degree of nonlinearity in the viscoelastic properties of tissue: MPD = (P2-D)/P1, where P1 and P2 are the first and second peak displacement achieved in tissue by the first and second ARF excitations, respectively, and d is the ARF-induced displacement remaining at the time of the second push. |
once every 4 months for 4 years for 12 total measures |
|
Secondary |
Rate of change in DP ARF marginal peak displacement |
rates of change in marginal peak displacement will be measured from time-point to time-point (every 4 months) and across multiple time points (spanning 8 months to 4 years). |
4 months to 4 years |
|
Secondary |
Change in quantitative muscle testing score of maximum voluntary isometric contraction (MVIC) |
standard quantitative muscle testing of maximum voluntary isometric contraction (MVIC) in the rectus femoris, cranial sartorius, gastrocnemius, and lateral deltoid muscles of the right limbs. |
every 4 months for 4 years |
|
Secondary |
Change in time to rise from supine position to standing |
standard time to standing timed function test |
every 4 months for 4 years |
|
Secondary |
Change in distance walked in six minutes |
standard six-minute walk timed function test |
every 4 months for 4 years |
|
Secondary |
Change in time to walk 30 feet |
standard 30-feet walk timed function test |
every 4 months for 4 years |
|
Secondary |
Rate of change in maximum voluntary isometric contraction (MVIC) |
rate of change in maximum voluntary isometric contraction (MVIC) will be assessed from time-point to time-point (4 month separation between measures) and across time-points (8 months to 4 years time separation between measures). |
4 months to 4 years |
|
Secondary |
Rate of change in time to rise from supine to standing position |
rate of change in time to standing timed function test score will be assessed from time-point to time-point (4 month separation between measures) and across time-points (8 months to 4 years time separation between measures). |
4 months to 4 years |
|
Secondary |
Rate of change in distance walked in six minutes |
rate of change in six-minute walk timed function test score will be assessed from time-point to time-point (4 month separation between measures) and across time-points (8 months to 4 years time separation between measures). |
4 months to 4 years |
|
Secondary |
Rate of change in time to walk 30 feet |
rate of change in 30-feet walk timed function test score will be assessed from time-point to time-point (4 month separation between measures) and across time-points (8 months to 4 years time separation between measures). |
4 months to 4 years |
|
Secondary |
Age at loss of ambulation |
Loss of ambulation will be diagnosed by the patient volunteer's physician. The patient volunteer's age at the time loss of ambulation is first diagnosed will be recorded. |
4 years |
|
Secondary |
Change in percent degenerative muscle composition |
Muscle boundaries will be hand-delineated using matched B-Mode image guidance in DP ARF marginal peak displacement parametric images. Within each 2D muscle image, percent degenerative area (Ad) will be calculated as T/N, where N is the total muscle area (number of pixels x area/pixel) and T is the muscle area in which marginal peak displacement values are within thresholds for necrosis, fat or fibrous tissue identification. |
every 4 months for 4 years |
|
Secondary |
Change in percent necrotic tissue area |
Muscle boundaries will be hand-delineated using matched B-Mode image guidance in DP ARF marginal peak displacement parametric images. Within each 2D muscle image, percent necrotic area (An) will be calculated as n/N, where N is the total muscle area (number of pixels x area/pixel) and n is the muscle area in which marginal peak displacement values are within thresholds for necrosis. |
every 4 months for 4 years |
|
Secondary |
Change in percent fat tissue area |
Muscle boundaries will be hand-delineated using matched B-Mode image guidance in DP ARF marginal peak displacement parametric images. Within each 2D muscle image, percent fatty deposition area (Af) will be calculated as f/N, where N is the total muscle area (number of pixels x area/pixel) and f is the muscle area in which marginal peak displacement values are within thresholds for fat tissue identification. |
every 4 months for 4 years |
|
Secondary |
Change in percent fibrotic tissue area |
Muscle boundaries will be hand-delineated using matched B-Mode image guidance in DP ARF marginal peak displacement parametric images. Within each 2D muscle image, percent degenerative area (Ac) will be calculated as c/N, where N is the total muscle area (number of pixels x area/pixel) and c is the muscle area in which marginal peak displacement values are within thresholds for fibrous tissue identification. |
every 4 months for 4 years |
|