Clinical trial NCT05072652: Short Term Immobilization of the Lower Limb
Official title: Short-term Immobilization and Rehabilitation of the Lower Limb: Changes in Strength, Size, and Neuromuscular Function
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Weakness, Muscle
Muscle Weakness
Muscle Loss
Muscle Atrophy
Injury, Knee
Keywords: immobilization
muscle atrophy
muscle strength
action observation
mental imagery
neuromuscular electrical stimulation
rehabilitation
Lead sponsor: University of Central Florida
Sponsor class: OTHER
First posted: 2021-10-11
Enrollment: 50
Sex: ALL
Minimum age (years): 18
Maximum age (years): 40
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Intervention model description: Repeated measures design
Primary purpose: PREVENTION

Brief summary: The purpose of this study is to determine the effects of one week of knee-joint immobilization on muscle size, strength, neuromuscular function, and brain function. In addition, the effects of two different interventions (i.e., neuromuscular electrical stimulation and action observation/mental imagery) throughout immobilization will be determined. Following the immobilization period, participants that have lost strength will be rehabilitated with twice weekly resistance training sessions, and sex-based differences in rehabilitation timelines will be examined.

Detailed description: This study will utilize a repeated measures design in healthy adults aged 18-40 years. After a thorough familiarization visit, muscular size, strength, neuromuscular responses, and corticospinal excitability/inhibition will be measured before (PRE) and after (POST) one week of unilateral knee joint immobilization of the left leg. Four groups will be examined: 1) immobilization only, 2) immobilization + daily neuromuscular electrical stimulation, 3) immobilization + daily action observation/mental imagery training, 4) a control group. Throughout the immobilization period, participants will be in a leg brace locked at 90 degrees knee flexion. They will perform daily range of motion exercises and wear a compression sock at all times to mitigate the risk of blood clots. Following completion of the immobilization period, participants that have lost strength will complete a supervised rehabilitation program of twice weekly lower body resistance training sessions until they have returned to baseline levels of strength. Group assignment will be randomized and blocked on sex to ensure an equal number of participants within each group consisting of a relatively equal number of males and females.

Eligibility criteria: Inclusion Criteria:

* Healthy men and women between the ages of 18-40 years
* Body mass index \>20 kg/m2 or \< 35 kg/m2

Exclusion Criteria:

* Body mass index \<20 kg/m2 or \> 35 c
* Experience of major joint pain/discomfort of the upper or lower limbs, back, or neck within the previous six months.
* History of major musculoskeletal injury or surgery
* Neuromuscular disease (e.g., Parkinson's, MS, ALS)
* Metabolic disease (e.g., diabetes, thyroid disorder, metabolic syndrome)
* Personal or family history of blood clots
* Trouble using or controlling one's muscles
* History of cancer
* History of stroke
* History of heart attack
* History of arthritis
* Use of an assistive walking device or mobility aids within the past six months
* Use of anabolic steroids within the past six months
* History of convulsions, seizures, or syncope
* History of concussion as diagnosed by a physician
* Certain medications (e.g., muscle relaxants, benzodiazepines)
* Very thick hair or certain hairstyles that would impede the TMS coil from making direct contact with the scalp
* Allergy to rubbing alcohol
* Lack of transportation to and from the laboratory
* Implant of any kind
* Pregnancy
* Allergy to silver
* Diagnosis of any psychiatric condition

Primary outcomes:
measure: Muscular strength
timeFrame: 15 minutes
measure: Muscular size
timeFrame: 10 minutes
measure: Corticospinal responses
timeFrame: 30 minutes
measure: Motor unit behavior
timeFrame: 10 minutes
measure: Voluntary activation
timeFrame: 15 minutes
measure: Rate of recovery
timeFrame: 1.5 hours per session
Secondary outcomes:
measure: Compliance
timeFrame: one week
measure: Physical activity (Step count)
timeFrame: one week
Other outcomes:
Locations:
city: Orlando
country: United States
facility: University of Central Florida
state: Florida
Study officials:
affiliation: University of Central Florida
name: Matt S Stock, PhD
role: PRINCIPAL_INVESTIGATOR
References: