Clinical Trials in the Spotlight Main Page

The National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) supports a range of clinical trials studying new and existing interventions for prevention and treatment of arthritis, musculoskeletal, and skin diseases.  Investigators supported by the NIAMS need your help finding individuals to participate in clinical trials.  Participating in clinical trials allows you to play an active role as a volunteer in research and contribute to generating new knowledge about the disease/condition, and potentially future treatments.  The information below is designed to help you quickly learn about actively recruiting research studies for which you or someone you know may be eligible. 

Study Description

The number of individuals undergoing total knee replacement (TKR) each year continues to rise. While TKR is effective for improving pain and function, subsequent improvements in physical activity are not common. As a result, patients spend most of their day engaged in sedentary behavior, which may put them at higher risk of experiencing poor function and disability, as well as lower the overall success of the surgical treatment. Intervening on sedentary time, rather than physical activity, may be a more feasible first-step approach for modifying activity-related behaviors in this population. Therefore, the purpose of this innovative clinical trial is to use TKR as a teachable moment for implementing a sedentary reduction intervention. This study proposes to use a just-in-time mobile health (mHealth) intervention to reduce sedentary time among TKR patients.

Patients scheduled for TKR will be recruited to participate prior to surgery and then randomized at 4 weeks after surgery to either (1) NEAT!2 or (2) Control. NEAT!2 participants will use the NEAT!2 (Non-Exercise Activity Thermogenesis version 2) smartphone app until 3 months after surgery. The NEAT!2 app is designed to provide a vibration and/or audible tone to interrupt prolonged bouts of sitting detected from the smartphone’s internal accelerometer.

 The primary aim is to examine the effects of the NEAT!2 intervention on sedentary time at end of treatment (3 months) and maintenance (6 months). Secondary aims include examining the effects of the NEAT!2 intervention on physical function, physical activity, and pain as well as examining the dose response relationship between adherence to NEAT!2 and changes in outcomes. The proposed study will examine the innovative approach of decreasing sedentary time prior to targeting physical activity in adults after TKR and determine if a remotely-delivered, mHealth sedentary reduction intervention can decrease sedentary time.


Ages Eligible for Study:             40 Years to 79 Years   (Adult, Older Adult)

Sexes Eligible for Study:           All

Accepts Healthy Volunteers:  Yes

Inclusion Criteria:

  • Be 40-79 years of age
  • Plan to have a primary unilateral knee placement >10 days
  • Have an Android or iOS smartphone that is accessible and near them the majority of the day
  • Be willing to download the study applications on their smartphone
  • Spend at least 7 hours/day sitting
  • Be English speaking


Exclusion Criteria:

  • Have any contraindications to activity
  • Have a mobility limiting comorbidity
  • Have a scheduled surgery within the next 6 months
  • Do not have ≥4 days of valid accelerometer (>=10 hours) wear at baseline.

Study Design:

Allocation:       Randomized

Intervention Model: Parallel Assignment

Masking: Single (Outcomes Assessor)

Primary Purpose: Treatment

Study Location(s):

University of South Carolina, Columbia, South Carolina, United States, 29208

Study Website:


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