Muscle Function After Childbirth

NCT ID: NCT05073224

Last Updated: 2024-06-27

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: NA
• Total Enrollment: 78 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2022-09-20
• Study Completion Date: 2024-09-30

Brief Summary

This study will evaluate lower extremity and trunk neuromuscular control in 78 nulligravid and postpartum women. Participants will attend two experimental sessions, approximately 1 week apart, to assess neuromuscular function. Physical activity levels will also be assessed.

Detailed Description

Stability of the lumbar spine and pelvis is essential to nearly all activities of daily living, and is achieved primarily by muscular stabilization. Recent studies have shown that postpartum women are more fatigable than nulligravid women during fatiguing tasks with the lumbopelvic stabilizing muscles (23%) and the trunk flexor muscles (52%) at six months postpartum. Postpartum women also demonstrate impaired control of force with the trunk flexor muscles; however, it is unknown if force control during a fatiguing task of the lumbopelvic stabilizing muscles is impaired in postpartum women.

This study has 3 purposes: (1) To quantify limb steadiness during fatiguing exercise of the lumbopelvic stabilizing muscles among nulligravid women and postpartum women; (2) to quantify muscle activity in the trunk, test limb and contralateral limb to provide insight into motor control; and (3) to identify possible factors (inter-recti distance (IRD), physical activity, pain, biopsychosocial factors) that contribute to neuromuscular function (fatigability and force control).

This is a novel, translational study that, for the first time, will quantify lower extremity force control in postpartum women. As this has not been studied before, to the best of the investigators' knowledge, this proposal will be a pilot study to establish means to utilize in power analyses for future studies of larger magnitude. Furthermore, neuromuscular function is not typically assessed clinically in postpartum women, and no tests exist to easily assess fatigability of the lumbopelvic stabilizing muscles in clinic settings. This study will also provide further data to highlight the ASLR Fatigue Task as a possible clinical examination tool and outcome measure to assess fatigability of the lumbopelvic stabilizing muscles.

Conditions

Postpartum; Muscle Fatigue; Force Steadiness; Nulligravid; Muscle Weakness

Study Design

• Allocation Method: NON_RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: NONE

Study Groups

Postpartum

Participants who are six months postpartum will complete 2 experimental sessions, separated by 7-10 days. Participants will complete multiple questionnaires, maximal voluntary contractions of the lower extremity muscles, clinical tests of lumbopelvic neuromuscular control/posterior pelvic pain provocation, and fatiguing lower extremity/trunk muscle exercise. Ultrasound imaging will be performed to measure inter-recti distance. Wireless Electromyography (EMG) sensors will be used to record EMG and limb steadiness (via Inertial Measurement Units (IMU). Physical activity will be measured by questionnaire and accelerometer.

Group Type: EXPERIMENTAL

Active Straight Leg Raise Test

Intervention Type: DIAGNOSTIC_TEST

The ASLR test is a well-established clinical test that assesses stability of the lumbar spine/pelvis, posterior pelvic pain severity, and ability to activate the abdominal muscles. It is performed in supine. Participants are instructed to raise one leg, with the knee straight, to a heel height of 20 cm. The leg is held at the top for 5 seconds, then slowly lowered to the ground. The participant is asked to report perceived difficulty to raise the leg on a 0 to 5 scale (0=not at all difficult; 5=unable to lift leg) and pain on a 0 to 10 scale (0=no pain; 10=worst possible pain). If difficulty or pain are rated at a 1 or higher, the test is repeated with the researcher providing external compression of the pelvis. If perceived difficulty or reported pain are lower with compression, the test is considered positive for lumbopelvic instability. The test is then repeated on the opposite limb.

Active Straight Leg Raise Fatigue Task

Intervention Type: OTHER

The protocol is similar to the ASLR test, except that the participant is instructed to maintain the elevated leg off the ground for as long as possible. A biofeedback air cuff will be placed under the participant's lumbopelvic region to assess movement of the spine/pelvis. The cuff will be inflated to 40 mm Hg, and the participant instructed to keep the needle as close to 40 mm Hg as possible throughout the test; no information will be provided on how to affect cuff pressure, but visual feedback of cuff pressure will be provided throughout the task. Ratings of perceived exertion (RPE) and pain will be obtained from participants every 30-60 seconds. Task failure will be defined as a heel height ≤10 cm or a change in cuff pressure ≥20 mm Hg. Both limbs will be tested, but in different sessions. The order of limb testing (dominant vs non-dominant) will be randomized and counter-balanced. Limb dominance will be self-reported.

Lower Extremity Strength Testing

Intervention Type: OTHER

A straight leg raise maximal voluntary contraction (MVC) of each lower extremity an MVC of the hip extensors of the grounded limb will be performed in supine before and within 2 minutes of completing the ASLR fatigue task. The straight leg raise MVC will be performed with a custom-made load cell instrumented strength testing device, which consists of a rigid platform on which the participant will lie. At the foot of the device is a tower that houses 2 load cells connected to a lightly padded push plate.

The hip extension MVC will be performed on a force plate. Before the ASLR fatigue task, a minimum of 3 MVC trials will be performed for each muscle group, with a minimum of 1 minute rest between trials; the highest peak force will be considered the MVC. Only 1 MVC trial per muscle group will be performed following the ASLR Fatigue Task.

Ultrasound imaging of abdominal wall

Intervention Type: DIAGNOSTIC_TEST

Real time ultrasound will be used to assess inter-recti distance above and below the umbilicus. Participants will be assessed with B Mode images in supine at rest, in supine while lifting their head, and in supine while performing a straight leg raise. The Principle Investigator has training and experience in musculoskeletal ultrasound.

Nulligravid

Participants who have never been pregnant will complete 2 experimental sessions, separated by 7-10 days. Participants will complete multiple questionnaires, maximal voluntary contractions of the lower extremity muscles, clinical tests of lumbopelvic neuromuscular control/posterior pelvic pain provocation, and fatiguing lower extremity/trunk muscle exercise. Ultrasound imaging will be performed to measure inter-recti distance. Wireless EMG sensors will be used to record EMG and limb steadiness (via IMUs). Physical activity will be measured by questionnaire and accelerometer.

Group Type: ACTIVE_COMPARATOR

Active Straight Leg Raise Test

Intervention Type: DIAGNOSTIC_TEST

The ASLR test is a well-established clinical test that assesses stability of the lumbar spine/pelvis, posterior pelvic pain severity, and ability to activate the abdominal muscles. It is performed in supine. Participants are instructed to raise one leg, with the knee straight, to a heel height of 20 cm. The leg is held at the top for 5 seconds, then slowly lowered to the ground. The participant is asked to report perceived difficulty to raise the leg on a 0 to 5 scale (0=not at all difficult; 5=unable to lift leg) and pain on a 0 to 10 scale (0=no pain; 10=worst possible pain). If difficulty or pain are rated at a 1 or higher, the test is repeated with the researcher providing external compression of the pelvis. If perceived difficulty or reported pain are lower with compression, the test is considered positive for lumbopelvic instability. The test is then repeated on the opposite limb.

Active Straight Leg Raise Fatigue Task

Intervention Type: OTHER

The protocol is similar to the ASLR test, except that the participant is instructed to maintain the elevated leg off the ground for as long as possible. A biofeedback air cuff will be placed under the participant's lumbopelvic region to assess movement of the spine/pelvis. The cuff will be inflated to 40 mm Hg, and the participant instructed to keep the needle as close to 40 mm Hg as possible throughout the test; no information will be provided on how to affect cuff pressure, but visual feedback of cuff pressure will be provided throughout the task. Ratings of perceived exertion (RPE) and pain will be obtained from participants every 30-60 seconds. Task failure will be defined as a heel height ≤10 cm or a change in cuff pressure ≥20 mm Hg. Both limbs will be tested, but in different sessions. The order of limb testing (dominant vs non-dominant) will be randomized and counter-balanced. Limb dominance will be self-reported.

Lower Extremity Strength Testing

Intervention Type: OTHER

A straight leg raise maximal voluntary contraction (MVC) of each lower extremity an MVC of the hip extensors of the grounded limb will be performed in supine before and within 2 minutes of completing the ASLR fatigue task. The straight leg raise MVC will be performed with a custom-made load cell instrumented strength testing device, which consists of a rigid platform on which the participant will lie. At the foot of the device is a tower that houses 2 load cells connected to a lightly padded push plate.

The hip extension MVC will be performed on a force plate. Before the ASLR fatigue task, a minimum of 3 MVC trials will be performed for each muscle group, with a minimum of 1 minute rest between trials; the highest peak force will be considered the MVC. Only 1 MVC trial per muscle group will be performed following the ASLR Fatigue Task.

Ultrasound imaging of abdominal wall

Intervention Type: DIAGNOSTIC_TEST

Real time ultrasound will be used to assess inter-recti distance above and below the umbilicus. Participants will be assessed with B Mode images in supine at rest, in supine while lifting their head, and in supine while performing a straight leg raise. The Principle Investigator has training and experience in musculoskeletal ultrasound.

Interventions

Active Straight Leg Raise Test

The ASLR test is a well-established clinical test that assesses stability of the lumbar spine/pelvis, posterior pelvic pain severity, and ability to activate the abdominal muscles. It is performed in supine. Participants are instructed to raise one leg, with the knee straight, to a heel height of 20 cm. The leg is held at the top for 5 seconds, then slowly lowered to the ground. The participant is asked to report perceived difficulty to raise the leg on a 0 to 5 scale (0=not at all difficult; 5=unable to lift leg) and pain on a 0 to 10 scale (0=no pain; 10=worst possible pain). If difficulty or pain are rated at a 1 or higher, the test is repeated with the researcher providing external compression of the pelvis. If perceived difficulty or reported pain are lower with compression, the test is considered positive for lumbopelvic instability. The test is then repeated on the opposite limb.

Intervention Type: DIAGNOSTIC_TEST

Active Straight Leg Raise Fatigue Task

The protocol is similar to the ASLR test, except that the participant is instructed to maintain the elevated leg off the ground for as long as possible. A biofeedback air cuff will be placed under the participant's lumbopelvic region to assess movement of the spine/pelvis. The cuff will be inflated to 40 mm Hg, and the participant instructed to keep the needle as close to 40 mm Hg as possible throughout the test; no information will be provided on how to affect cuff pressure, but visual feedback of cuff pressure will be provided throughout the task. Ratings of perceived exertion (RPE) and pain will be obtained from participants every 30-60 seconds. Task failure will be defined as a heel height ≤10 cm or a change in cuff pressure ≥20 mm Hg. Both limbs will be tested, but in different sessions. The order of limb testing (dominant vs non-dominant) will be randomized and counter-balanced. Limb dominance will be self-reported.

Intervention Type: OTHER

Lower Extremity Strength Testing

A straight leg raise maximal voluntary contraction (MVC) of each lower extremity an MVC of the hip extensors of the grounded limb will be performed in supine before and within 2 minutes of completing the ASLR fatigue task. The straight leg raise MVC will be performed with a custom-made load cell instrumented strength testing device, which consists of a rigid platform on which the participant will lie. At the foot of the device is a tower that houses 2 load cells connected to a lightly padded push plate.

The hip extension MVC will be performed on a force plate. Before the ASLR fatigue task, a minimum of 3 MVC trials will be performed for each muscle group, with a minimum of 1 minute rest between trials; the highest peak force will be considered the MVC. Only 1 MVC trial per muscle group will be performed following the ASLR Fatigue Task.

Intervention Type: OTHER

Ultrasound imaging of abdominal wall

Real time ultrasound will be used to assess inter-recti distance above and below the umbilicus. Participants will be assessed with B Mode images in supine at rest, in supine while lifting their head, and in supine while performing a straight leg raise. The Principle Investigator has training and experience in musculoskeletal ultrasound.

Intervention Type: DIAGNOSTIC_TEST

Other Intervention Names

ASLR Test; ASLR Fatigue Task

Eligibility Criteria

Inclusion Criteria

• Post-partum
• Primiparous (this is their first child)

Exclusion Criteria

• multiple gestation
• prescription anti-inflammatory/pain medications that are taken daily
• significant orthopedic conditions that would contraindicate performance of the fatigue task (such as fractures, severe scoliosis, etc)
• cardiovascular & pulmonary disease
• neuromuscular health conditions (such as diabetes, neuropathy, multiple sclerosis, stroke, seizures, etc)
• history of previous abdominal surgery (with the exception of Cesarean delivery)

Nulligravid Women (Controls)

• Women from the surrounding community will also be recruited to serve as controls

• Minimum Eligible Age: 20 Years
• Maximum Eligible Age: 35 Years
• Eligible Sex: FEMALE
• Accepts Healthy Volunteers: Yes

Sponsors

Carroll University

OTHER

Sponsor Role: lead

Responsible Party

Rita Deering

Associate Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Rita Deering, PT, DPT, PhD

Role: PRINCIPAL_INVESTIGATOR

Carroll University

Locations

Carroll University

Waukesha, Wisconsin, United States

Site Status: RECRUITING

Carroll University

Waukesha, Wisconsin, United States

Site Status: RECRUITING

Countries

United States

Central Contacts

Rita Deering, DPT, PhD

Role: CONTACT

rdeering@carrollu.edu

2629513047

Facility Contacts

Rita Deering, PT, DPT, PhD

Role: primary

rdeering@carrollu.edu

262-951-3047

Rita Deering, PT, DPT, PhD

Role: primary

rdeering@carrollu.edu

Other Identifiers

A536130

Identifier Type: OTHER

Identifier Source: secondary_id

Protocol Version 6/9/2020

Identifier Type: OTHER

Identifier Source: secondary_id

2019-0275

Identifier Type: -

Identifier Source: org_study_id