Interventions to Enhance Quadriceps Output After ACLR

Clinical Interventions to Acutely Enhance Quadriceps Output After Anterior Cruciate Ligament Reconstruction

The investigators are interested in determining what treatments are effective in reducing inhibition after anterior cruciate ligament (ACL) surgery and helping people increase quadriceps strength. Two interventions that are often used clinically are neuromuscular electrical stimulation (NMES) and vibration. This is a study of how effective these treatments are, whether they work the same for everyone, and if one is better than the other. 22 participants will be enrolled and on study for 2 to 3 weeks.

Study Overview

• Status: Not yet recruiting
• Conditions: ACL
• Intervention / Treatment: Device: NMES; Device: Vibration

Detailed Description

After a screening visit, participants will be randomized to 2 intervention conditions over 2, 60-minute visits at least 1 week apart where they will complete:

• a 5 minute low intensity warm-up on a stationary bike
• a series of patient-reported outcomes surveys
• a pre-intervention quadriceps performance assessment

• the intervention condition, one each visit, either:

  • ~20 minutes of NMES while completing rehabilitation exercises, OR
  • ~20 minutes of hamstring muscle vibration
• a post-intervention quadriceps performance assessment

The primary objective of the study is to characterize the acute effects of interventions designed to mitigate the influence of inhibition (NMES and hamstrings muscle vibration) on quadriceps muscle performance in people post-anterior cruciate ligament reconstruction (ACLR) who have significant potential to benefit from these interventions (e.g. less than 4 months post-surgery).

• Specific Aim 1: To determine the acute effects of quadriceps NMES and hamstrings muscle vibration on quadriceps muscle performance in people 2-4 months post-ACLR
• Specific Aim 2: To determine if individuals with signs of more pronounced neural inhibition (quantified via assessment of knee extensor torque steadiness) have greater responses to NMES and hamstrings muscle vibration

Hypothesis 1: Quadriceps muscle strength will increase in people 2-4 months post-ACLR after 20 minutes of quadriceps NMES or hamstrings muscle vibration. The magnitude of increase in strength will be similar for both interventions.

Hypothesis 2: Surgical limb knee extensor torque steadiness will be strongly positively correlated with changes in quadriceps strength after NMES or hamstrings muscle vibration. People with greater steadiness impairments will demonstrate greater acute increases in quadriceps strength.

• Study Type: Interventional
• Enrollment (Estimated): 22
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Daniel Cobian, DPT, PhD; Phone Number: 608-262-0013; Email: cobian@ortho.wisc.edu

Study Locations

• United States
  • Wisconsin
    • Madison, Wisconsin, United States, 53706
      • UW Health

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Have undergone ACLR within the previous 4 months
• Are at least 2 months post-ACLR

Exclusion Criteria:

• A history of ACLR on both legs

• Since the most recent ACLR:

  • secondary lower extremity surgery
  • leg or foot fracture
• Unable to walk without an assistive device
• Pain of greater than 5/10 during quadriceps strengthening exercises with the surgical limb
• Cannot achieve 90 degrees of knee flexion with the surgical limb
• People with contraindications to NMES
• Anyone who had a previous skin reaction to NMES or attempted but could not tolerate NMES
• Peripheral neuropathy or other neurological conditions

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: NMES then Vibration	Device: NMES; The thigh of the surgical leg will be cleaned with isopropyl alcohol. 2.75" x 5" NMES electrodes (Dura-Stick Plus, Chattanooga, DJO Global, Dallas, TX) will be adhered to the proximal and distal aspects of the quadriceps muscles. An FDA-approved portable neuromuscular electrical stimulator (Empi Continuum, DJO Global, Dallas, TX) will be utilized to deliver a biphasic square wave pulse (frequency 75 Hz, pulse width 300 µs) to the quadriceps of the surgical limb. Participants will control both the amplitude of current delivered (0-100 mA) and the on/off timing of the stimulation via a wired control switch. Participants will complete common post-ACLR rehabilitation exercises while NMES is delivered (total time for exercises is approximately 20 minutes).; Other Names: Empi Continuum; Device: Vibration; Participants will sit in a comfortable position on a treatment plinth with knees flexed to ~30°, hips flexed between 30-60°, and the back supported. The back of the thighs will rest on the vibration pads of a commercial vibration device (Thumper Versa Pro Massager, (Thumper Massager Inc., Markham, Ontario, CA). Participants will sit at rest for 20 minutes while the vibration device provides a 30 Hz vibration with an amplitude of ~6 mm.; Other Names: Thumper Versa Pro
Experimental: Vibration then NMES	Device: NMES; The thigh of the surgical leg will be cleaned with isopropyl alcohol. 2.75" x 5" NMES electrodes (Dura-Stick Plus, Chattanooga, DJO Global, Dallas, TX) will be adhered to the proximal and distal aspects of the quadriceps muscles. An FDA-approved portable neuromuscular electrical stimulator (Empi Continuum, DJO Global, Dallas, TX) will be utilized to deliver a biphasic square wave pulse (frequency 75 Hz, pulse width 300 µs) to the quadriceps of the surgical limb. Participants will control both the amplitude of current delivered (0-100 mA) and the on/off timing of the stimulation via a wired control switch. Participants will complete common post-ACLR rehabilitation exercises while NMES is delivered (total time for exercises is approximately 20 minutes).; Other Names: Empi Continuum; Device: Vibration; Participants will sit in a comfortable position on a treatment plinth with knees flexed to ~30°, hips flexed between 30-60°, and the back supported. The back of the thighs will rest on the vibration pads of a commercial vibration device (Thumper Versa Pro Massager, (Thumper Massager Inc., Markham, Ontario, CA). Participants will sit at rest for 20 minutes while the vibration device provides a 30 Hz vibration with an amplitude of ~6 mm.; Other Names: Thumper Versa Pro

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Change in knee extensor peak torque production	measured pre-intervention and post-intervention during each of 2, 1-hour study visits, data collection complete within 3 weeks

Secondary Outcome Measures

Outcome Measure	Time Frame
Change in knee extensor torque steadiness	measured pre-intervention and post-intervention during each of 2, 1-hour study visits, data collection complete within 3 weeks

Collaborators and Investigators

• Sponsor: University of Wisconsin, Madison
• Investigators: Principal Investigator: Daniel Cobian, DPT, PhD, University of Wisconsin, Madison

Study record dates

Study Major Dates

• Study Start (Estimated): June 1, 2026
• Primary Completion (Estimated): June 1, 2027
• Study Completion (Estimated): June 1, 2027

Study Registration Dates

• First Submitted: June 24, 2026
• First Submitted That Met QC Criteria: June 24, 2026
• First Posted (Actual): June 30, 2026

Study Record Updates

• Last Update Posted (Actual): June 30, 2026
• Last Update Submitted That Met QC Criteria: June 24, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: neuromuscular electrical stimulation; vibration; quadriceps; ACLR
• Other Study ID Numbers: 2026-0153; Protocol Version 10/24/25 (Other Identifier: UW Madison); SMPH | Ortho and Rehab (Other Identifier: UW Madison)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: Yes