SSL* contains variables: maximum amplitude (Newton*Meter for moment) during preload and peak thrust force in anterior-posterior (X), side-to-side (Y), head-to-toe direction (Z) and combined force (C).

*Interpretation: the purpose of the outcomes is to quantify force-time profile of SM. The values of the outcome depend on the doctor who delivers SM, location and direction of SM, participant body position, and equipment. Currently there is no consensus regarding what value is higher than normal, normal, or lower than normal.

Sign convention: because patient position would affect the sign of some measurements, the right side up position was used as the reference position (i.e., the affected measurements assessed in the left side up position had their sign inverted) in order to calculate mean and SD. The value reported is the change from baseline to week 6.

SSL* contains variables: rate of loading for force in anterior-posterior (X), side-to-side (Y), head-to-toe direction (Z) and combined force (C).

*Interpretation: the purpose of the outcomes is to quantify force-time profile of SM. The values of the outcome depend on the doctor who delivers SM, location and direction of SM, participant body position, and equipment. Currently there is no consensus regarding what value is higher than normal, normal, or lower than normal.

Sign convention: because patient position would affect the sign of some measurements, the right side up position was used as the reference position (i.e., the affected measurements assessed in the left side up position had their sign inverted) in order to calculate mean and SD. The value reported is the change from baseline to week 6.

SSL* contains variables: rate of loading for moment in anterior-posterior (X), side-to-side (Y), head-to-toe direction (Z) and combined force (C).

*Interpretation: the purpose of the outcomes is to quantify force-time profile of SM. The values of the outcome depend on the doctor who delivers SM, location and direction of SM, participant body position, and equipment. Currently there is no consensus regarding what value is higher than normal, normal, or lower than normal.

Sign convention: because patient position would affect the sign of some measurements, the right side up position was used as the reference position (i.e., the affected measurements assessed in the left side up position had their sign inverted) in order to calculate mean and SD. The value reported is the change from baseline to week 6.

1) The questionnaire contains 7 PROMIS-29 specific items: Anxiety, Depression, Fatigue, Pain Interference, Physical Function, Sleep Disturbance, and Satisfaction with Participation in Social Role (anchors: 1= 'Not at all', 5= 'Very much', higher score is worse).

Each PROMIS-29 specific item is reported in raw score (4-20) and scored in T-score (T), which rescales the raw score into a standardized score with a mean of 50 and a standard deviation (SD) of 10 for a population.

On the T-score metric & interpretation:

• A score of 40 is one SD lower than the mean of the reference population.
• A score of 60 is one SD higher than the mean of the reference population.
• For PROMIS measures, higher scores equals more of the concept being measured (e.g., more Fatigue, more Physical Function). Thus a score of 60 is one standard deviation above the average referenced population. This could be a desirable or undesirable outcome, depending upon the concept being measured.

1) The PROMIS questionnaire contains 1 PROMIS global item: Pain NRS, Scale: 0-10 (anchors: 0 = No Pain, 10 = Worst Imaginable Pain, higher score is worse). The PROMIS global item is not scored but reported in raw score.

Question asked of participants: "During the past week, how bothersome have each of the following symptoms been?" The bothersomeness questionnaire contains two items: a) low back pain & b) leg pain (sciatica).

Scale: 0-10 (anchors: 0 = Not at all bothersome, 10 = Extremely bothersome)

VAS - Visual Analog Scale: The VAS is a single-item, unidimensional measure for pain. Score interpretations for the VAS include the following cut points: no pain (0 to 4 mm), mild pain (5 to 44 mm), moderate pain (45 to 74 mm), and severe pain (75 to 100 mm).

RMDQ - Roland Morris disability questionnaire: The RMDQ consists of 24 questions related to disability, with each question worth one point. Scores can range from 0 (no disability) to 24 (severe disability).

LSS* contains 5 variables: global stiffness (GS, unit: Newton/mm) at L3 from 1) hand palpation 2) a hand-held device & 3) an automated indenter device; global stiffness variation (GSV, unit: Newton/mm) between GS from L1 to L5 from 4) hand palpation & 5) a hand-held device.

*LSS Interpretation: The values of the outcome depend on testing procedure, instruction to participants, and equipment. Currently there is no consensus regarding what value is high than normal, normal, lower than normal.

82, 71 and 68 participants completed at baseline, after 2 weeks and after 6 weeks, respectively. The number of observations at each of the 3 time points for individual measures is equal to or lower than these numbers due to missing data.

LSS contains 2 variables: Palpatory and Handheld device - normalized global stiffness variation (nGSV, unitless).

LSS Interpretation: The values of the outcome depend on testing procedure, instruction to participants, and equipment. Currently there is no consensus regarding what value is higher than normal, normal, lower than normal.

FRR contains 4 variables, which are the average right and left back muscle FRR obtained using 1) maximum EMG during flexion, and 2) maximum EMG during extension to normalize EMG during full flexion; and asymmetry between the right and left back muscle FRRs using 3) maximum EMG during flexion, and 4) maximum EMG during extension to normalize EMG during full flexion

FRR Interpretation: The values of the outcome depend on testing procedure, instruction to participants, and equipment. Currently there is no consensus regarding what value is high than normal, normal, lower than normal.

SSL* contains variables: maximum amplitude (Newton) during preload and peak thrust force in anterior-posterior (X), side-to-side (Y), head-to-toe direction (Z) and combined force (C).

*Interpretation: the purpose of the outcomes is to quantify force-time profile of SM. The values of the outcome depend on the doctor who delivers SM, location and direction of SM, participant body position, and equipment. Currently there is no consensus regarding what value is higher than normal, normal, or lower than normal.

Sign convention: because patient position would affect the sign of some measurements, the right side up position was used as the reference position (i.e., the affected measurements assessed in the left side up position had their sign inverted) in order to calculate mean and SD. The value reported is the change from baseline to week 6.

Note: 82, 71 and 68 participants completed at baseline, after 2 weeks and after 6 weeks, respectively, and a total of 593 SM was delivered during visits 1, 5, and 12. The number of observations for individual measures is lower than the total number of analyzable SM (n=575) due to missing data in corresponding components.

SSL* contains variables: maximum amplitude (Newton*Meter for moment) during preload and peak thrust force in anterior-posterior (X), side-to-side (Y), head-to-toe direction (Z) and combined force (C).

*Interpretation: the purpose of the outcomes is to quantify force-time profile of SM. The values of the outcome depend on the doctor who delivers SM, location and direction of SM, participant body position, and equipment. Currently there is no consensus regarding what value is higher than normal, normal, or lower than normal.

Sign convention: because patient position would affect the sign of some measurements, the right side up position was used as the reference position (i.e., the affected measurements assessed in the left side up position had their sign inverted) in order to calculate mean and SD. The value reported is the change from baseline to week 6.

Note: 82, 71 and 68 participants completed at baseline, after 2 weeks and after 6 weeks, respectively, and a total of 593 SM was delivered during visits 1, 5, and 12. The number of observations for individual measures is lower than the total number of analyzable SM (n=575) due to missing data in corresponding components.

SSL* contains variables: rate of loading for force in anterior-posterior (X), side-to-side (Y), head-to-toe direction (Z) and combined force (C).

*Interpretation: the purpose of the outcomes is to quantify force-time profile of SM. The values of the outcome depend on the doctor who delivers SM, location and direction of SM, participant body position, and equipment. Currently there is no consensus regarding what value is higher than normal, normal, or lower than normal.

Sign convention: because patient position would affect the sign of some measurements, the right side up position was used as the reference position (i.e., the affected measurements assessed in the left side up position had their sign inverted) in order to calculate mean and SD. The value reported is the change from baseline to week 6.

Note: 82, 71 and 68 participants completed at baseline, after 2 weeks and after 6 weeks, respectively, and a total of 593 SM was delivered during visits 1, 5, and 12. The number of observations for individual measures is lower than the total number of analyzable SM (n=575) due to missing data in corresponding components.

SSL* contains variables: rate of loading for moment in anterior-posterior (X), side-to-side (Y), head-to-toe direction (Z) and combined force (C).

*Interpretation: the purpose of the outcomes is to quantify force-time profile of SM. The values of the outcome depend on the doctor who delivers SM, location and direction of SM, participant body position, and equipment. Currently there is no consensus regarding what value is higher than normal, normal, or lower than normal.

Sign convention: because patient position would affect the sign of some measurements, the right side up position was used as the reference position (i.e., the affected measurements assessed in the left side up position had their sign inverted) in order to calculate mean and SD. The value reported is the change from baseline to week 6.

Note: 82, 71 and 68 participants completed at baseline, after 2 weeks and after 6 weeks, respectively, and a total of 593 SM was delivered during visits 1, 5, and 12. The number of observations for individual measures is lower than the total number of analyzable SM (n=575) due to missing data in corresponding components.

1) The questionnaire contains 7 PROMIS-29 specific items: Anxiety, Depression, Fatigue, Pain Interference, Physical Function, Sleep Disturbance, and Satisfaction with Participation in Social Role (anchors: 1= 'Not at all', 5= 'Very much', higher score is worse).

Each PROMIS-29 specific item is reported in raw score (4-20) and scored in T-score (T), which rescales the raw score into a standardized score with a mean of 50 and a standard deviation (SD) of 10 for a population.

On the T-score metric & interpretation:

• A score of 40 is one SD lower than the mean of the reference population.
• A score of 60 is one SD higher than the mean of the reference population.
• For PROMIS measures, higher scores equals more of the concept being measured (e.g., more Fatigue, more Physical Function). Thus a score of 60 is one standard deviation above the average referenced population. This could be a desirable or undesirable outcome, depending upon the concept being measured.

Note: 82, 71 and 68 participants completed at baseline, after 2 weeks and after 6 weeks, respectively. Number of observations made at the three time points were 82, 70, and 68, respectively.

1) The PROMIS questionnaire contains 1 PROMIS global item: Pain NRS, Scale: 0-10 (anchors: 0 = No Pain, 10 = Worst Imaginable Pain, higher score is worse). The PROMIS global item is not scored but reported in raw score.

Note: 82, 71 and 68 participants completed at baseline, after 2 weeks and after 6 weeks, respectively. Number of observations made at the three time points were 82, 70, and 68, respectively.

Question asked of participants: "During the past week, how bothersome have each of the following symptoms been?" The bothersomeness questionnaire contains two items: a) low back pain & b) leg pain (sciatica).

Scale: 0-10 (anchors: 0 = Not at all bothersome, 10 = Extremely bothersome)

Note: 82, 71 and 68 participants completed at baseline, after 2 weeks and after 6 weeks, respectively. Number of observations made at the three time points were 82, 70, and 68, respectively.