Effect of TA Contraction on Gait in Patients With Knee OA

This will be the first study on this topic performed by the investigator. Regarding current
knowledge gaps, evidence has shown an influence of core strength measures/stability on lower
extremity function. This relationship has been examined very little in patients with knee OA;
however, evidence does show a correlation exists. There have been no studies examining the
effect of a core strengthening/stability intervention on lower extremity kinetics in patients
with knee OA to the PIs knowledge.

This is the first study examining the effects of TA contraction knee loading during gait in
this population.

Current evidence shows that core activation/stability may play a role in lower extremity
kinetics and kinematics. Most research has focused on younger, more athletic individuals.
Research on this population has in the past looked at patellofemoral disorders or ligamentous
injury. For example, decreased core function has been shown to increase the risk of
sustaining anterior cruciate ligament injury. In addition, increased core stability has
resulted in decreased knee loading during athletic activities.

There continues to be an overall paucity of research on proper prescription and dosage of
therapeutic exercise for patients with knee OA. Evidence has shown that quadriceps
strengthening and aerobic conditioning do lead to decreased disability. Additionally,
patients with knee osteoarthritis have decreased postural stability as compared to healthy
controls, with a significant correlation being observed between their score on a postural
stability measure and the Western Ontario and McMaster Universities Osteoarthritis Index.
Patients with knee OA also exhibit decreased overall core stability as compared to healthy
controls. This body of research however does not include any evidence on the effects of a
core stability intervention on improving overall function.

Knee OA leads to abnormalities in kinetic loading of the lower extremity during ambulation.
An increase in T1 in this population has been observed when comparing to healthy controls.
Separately, studies have shown that in patients with knee OA, knee joint loading can be
influenced by intraarticular hyaluronic acid injections, resulting in decreased T1.
Therefore, this study will explore the idea of how activation of a muscle (TA), which plays a
large role in core stability, influences kinetic loading (T1) during ambulation in patients
with knee OA.

Each participant will only be required to participate for one session, lasting about 1 hour.
This does not included the informed consent process requiring approximately 30 minutes of
their time prior to participation. Approximately 5 months will be required to enroll all
participants. It is the PI's goal to complete primary data analysis no more than 3 months
after data collection is complete, so total estimated study time is 8 months.

The primary study endpoint will be the cessation of data collection and the participants'
active participation in the research program. The Secondary endpoint will be the completion
of data analysis, which concludes the management of PHI.

Primary (exposure to any physical risk) and secondary (management of PHI) safety endpoints
are synonymous with the study endpoints mentioned in 8.1.

This project serves as pilot study for future investigation on the role of core stabilization
on gait kinetics in patients with knee OA. Therefore the sample size will be small. Post-hoc
power analysis will inform the PI about requirements for participant recruitment needs for
future investigations.

After informed consent is completed, participants will be scheduled for a session in the
Motion Analysis Laboratory in the SAHP. Patients will have already been asked to wear close
fitting, exercise appropriate clothing to allow marker placement, and prevent marker blocking
during motion analysis. Data collection will begin by collecting the following anthropometric
data: body weight (pounds, converted to kilograms) via a scale, height (inches, converted to
mm) via a tape measure, leg length from ipsilateral anterior superior iliac spine to
ipsilateral medial malleolus bilaterally (cm) via tape measure, and knee and ankle joint
widths (cm) via a caliper. After collection of this data is completed and recorded, the PI
will place reflective markers on the patient's skin via adhesive tape made for this purpose
at the following landmarks bilaterally: ASIS, posterior superior iliac spine, lateral thigh,
knee center of rotation, lateral leg, heel, lateral malleolus, and base of the second
metatarsal. When this set-up is complete, static calibration of the motion analysis system
will take place with the participant standing still in the capture area. When this is
complete, the participant will be allowed a 2-minute warm-up by walking back and forth in the
capture area. When this is completed the participant will be asked to walk at a comfortable
pace across the capture area. Three trials with good force plate contact will be collected.
After these three trials are obtained, the patient will lie supine on the mat in the lab, and
will be taught how to perform a TA contraction. A Pathway MR-20 biofeedback device (The
Prometheus Group, Dover, NH, USA) with two electrodes will be placed just medial to the ASISs
on the participant's abdomen. A baseline maximal contraction will be performed supine, and
the amplitude of contraction will be considered maximal voluntary isometric contraction
(MVIC). The device will be set to provide audible feedback at 50% MVIC. The task will be
repeated seated, standing, then ambulating three practice trials on the capture area. The
participant will then be instructed to perform an additional three comfortable paced
ambulation trials with good force plate contact while contracting the TA enough to cause
audible feedback via the biofeedback device. After completing these three trials, the
biofeedback device and reflective markers will be removed, and the participant will have
completed their active participation in the study.

Inclusion Criteria:

- those with medical diagnosis (providing written evidence from a physician, physician
assistant, or nurse practitioner) of knee OA unilaterally or bilaterally.

Exclusion Criteria:

- bilateral total knee arthroplasty, requirement of an assistive device or assistance
with ambulation, spinal diagnoses which contraindicate participation in spinal
stabilization activities, and those currently limited by another lower extremity
pathology at the time of participation.