Electromyostimulation and Strength Walking for Knee Injuries

The prevalence of knee injuries has shown a striking increase of >24% over the last 5 years,
affecting work performance, limiting mobility, and impacting military deployment health. This
increase reflects the current high op-tempo and frequent deployments of a nation at war
including activities related to military operations, physical fitness, and demanding
training. We have shown that neuromuscular electrical stimulation (NMES) improves quadriceps
muscle strength. We have also shown that a pedometer-based protocol improves fitness. The
overall objective of this project is to compare three treatment regimens for knee injury to
the standard rehabilitation protocol as potential treatments for improving strength, work
efficiency, and mobility in active duty military personnel with a knee injury. Our central
hypothesis is that the combination of NMES and walking while wearing a weighted vest will
demonstrate greater improvements in muscle strength, work efficiency, and mobility, as
compared to the usual care alone. The rationale is that NMES combined with graduated strength
walking could produce marked improvements in muscle strength and thereby enhance work
performance, readiness and fitness, decrease physical symptoms and faster return to duty.
NMES and graduated strength walking, simulate the current uniform in the theatre of operation
(body armor).The specific aims are to compare the effectiveness of three treatment regimens
to the usual care in improving: (1) muscle strength, (2) work efficiency, (3) mobility, (4)
symptoms/pain, and (5) quality of life. After baseline testing, we propose to randomly assign
male and female subjects (n=132) ages 18 to 50 years with a knee injury to one of 4 groups:
1) NMES, 2) strength walking, 3) NMES and strength walking, or 4) usual care. All groups will
receive 12-weeks of the intervention and 6-weeks of follow-up. Generalized estimating
equation (GEE) methods will be used to build regression models for statistical analysis of
longitudinal data. If the interventions are effective with respect to parameters of strength,
mobility, work performance, and symptoms, recommendations for future treatments can be made.
This is hugely important, given the rising rate of knee injuries and the possibility that
provider-managed care would be critical for assisting our warriors in a rapid recovery and
return to duty.

Inclusion Criteria:

- A diagnosis of knee injury (internal derangement of the knee with new effusion,
including knee sprain or strains, meniscal tear, cruciate ligamentous tear, and
chondral flap or injury);

- A diagnosis of knee pain that is anterior knee pain, overuse pain, patella-femoral
pain, and chronic pain (less than 6 months) associated with overuse syndromes which
negatively impacts performance by (a) pain in 1 or both knees on most days of the
month; b) self reported difficulty performing at least one or more tasks due to pain:
stair climbing, rising from a chair, walking or running a quarter mile, repetitive
movements such as kneeling or squatting or stooping, pain that inhibits job
performance and daily activities;

- Military service member at the time of injury (active duty military and Reserve/
National Guard in active duty status);

- Age ≥18 and ≤50 years;

- Ability to provide freely given informed consent.

Exclusion Criteria:

- Fracture or injury to external knee structures such that knee extension or flexion is
impaired;

- Evidence of a fracture on radiographs or clinical evidence of unstable tendon
tear/rupture;

- A significant co-morbid medical condition (such as severe hypertension or neurological
disorder in which NMES strength training or unsupervised exercise is contraindicated
and would pose a safety threat or impair ability to participate;

- Inability or unwillingness to participate in a walking or strengthening program;

- Inability to speak and/or read English;

- Reduced sensory perception in the lower extremities;

- Inability to walk on a treadmill without an assistive device;

- Vision impairment, where participant is classified as legally blind;

- Unwillingness to accept random assignment;

- Pregnancy;

- A score of 23 or greater on the Center for Epidemiological Studies- Depression scale
(CES-D);

- If the person has a demand type implanted pacemaker or defibrillator.