Patients that are on mechanical ventilators in medical intensive care units (MICU) have extremely weak leg muscles. Currently there is no treatment to prevent or reverse this weakness. Treatments with a thigh muscle stimulator, called an All Stim 2, can improve leg muscle strength and help patients regain leg function after knee surgery. The purpose of the present study is to determine if treatments with the All Stim 2 device can also improve leg muscle strength in patients on mechanical ventilation.



Eligible Ages
Over 18 Years
Eligible Genders
Accepts Healthy Volunteers

Inclusion Criteria

  • Adult patients requiring mechanical ventilation for more than 48 hours
  • Respiratory failure present

Exclusion Criteria

  • The physician caring for the patient determines that the patient is too unstable
  • Use of high dose pressors (more than 15 mcg/min of norepinephrine or more than 15 mg/kg/min of dopamine)
  • Use of more than 80% FiO2 (fractional concentration of oxygen) or more than 15 cm H2O (water) of PEEP (positive end expiratory pressure)
  • Presence of a cardiac pacemaker or implanted defibrillator
  • Use of neuromuscular blocking agents within the 48 hours preceding testing
  • History of a preexisting neuromuscular disease
  • Presence of profound and uncorrectable hypokalemia (less than 2.5) or hypophosphatemia (less than 1.0)
  • Pregnancy
  • If the patient is a prisoner
  • If the patient is institutionalized
  • If it is thought that the patient will have care withdrawn within 7 days

Study Design

Study Type
Intervention Model
Parallel Assignment
Primary Purpose
Single (Participant)

Arm Groups

ArmDescriptionAssigned Intervention
Sham Comparator
Sham electrical stimulation
The intervention will consist of sham electrical stimulation using an All Stim stimulator of each quadriceps leg muscle for 30 minutes per day for a total of 7 days.
  • Device: Sham electrical stimulation using an All Stim stimulator
    With this intervention the All Stim unit is turned off and no electrical stimulation is provided.
Active Comparator
Active electrical stimulation
The intervention will consist of active electrical stimulation using an All Stim stimulator of each quadriceps leg muscle for 30 minutes per day for a total of 7 days.
  • Device: Active electrical stimulation using an All Stim stimulator
    This is an FDA approved stimulator that is used for strengthening the quadriceps muscle.

Recruiting Locations

UK Center for Clinical and Translational Science and nearby locations

Chandler Hospital
Lexington, Kentucky 40536
Gerald Supinski, MD

More Details

Gerald Supinski

Study Contact

Gerald S Supinski, MD

Detailed Description

The objective for this study is to determine if daily exercise using All-Stim 2 stimulation of quadriceps muscles will increase leg strength and improve outcomes (duration of hospitalization, long term mobility, long term disability) for mechanically ventilated MICU patients. The investigators plan to randomize patients accepted into this protocol to administration of either sham exercise (i.e. placement of All-Stim 2 units on the legs for 30 minutes a day without activation of the electrical stimulation program) or active exercise (placement of All-Stim 2 electrodes on both legs and stimulating quadriceps muscles to rhythmically contract for 30 minutes a day). The two groups (sham and active exercise) will be treated for 30 minutes a day for seven days. The effects of exercise on quadriceps strength will be assessed by measuring quadriceps force generation (QuadTw) in response to magnetic stimulation of the femoral nerves. The QuadTw assessment will be made immediately before institution of sham or active exercise and will repeated one day after the conclusion of the seven day training regimen. Chart review and patient follow-up will be used to determine if this treatment regimen also has an impact on clinical outcome measures, i.e. duration of hospitalization.


Study information shown on this site is derived from (a public registry operated by the National Institutes of Health). The listing of studies provided is not certain to be all studies for which you might be eligible. Furthermore, study eligibility requirements can be difficult to understand and may change over time, so it is wise to speak with your medical care provider and individual research study teams when making decisions related to participation.