Orthopaedic Surgery and Rehabilitation

 
 
 
 
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Motion Analysis

    Under the direction of Louis Draganich, PhD, research in the Motion Analysis Laboratory is focused on the following areas:

1) The biomechanics of gait in young and older adults when stepping over an obstacle.

2) The effects of knee and hip osteoarthritis on gait, stair stepping and obstacle avoidance.

3) The effects of total knee arthroplasty and total hip arthroplasty on gait, stair stepping and obstacle avoidance.

4) The effects of orthoses and physical therapy on the gait and stair stepping of patients with acquired flatfoot deformity.

5) The effects of the self-adjustable valgus “unloader” brace on gait, stair stepping, pain, stiffness and function.

    Falling is the leading cause of death due to injury in the elderly, and tripping on an obstacle is the leading cause of falls. Osteoarthritis is a risk factor for falls, and knee osteoarthritis (KOA) is one of the leading causes of disability in the elderly. Total knee Arthroplasty (TKA) is primarily used to treat KOA. TKA improves pain and function, but does not return completely normal gait or stair stepping.

    Dr. Draganich is investigating the effects of walking speed on obstacle crossing in young and older healthy adults, challenging the subjects to step over obstacles more quickly than normal to learn about the effects of age on obstacle crossing. A preliminary analysis demonstrated that larger demands are placed on the hip and ankle abductors of the trailing limb of older adults to maintain dynamic balance when stepping over the obstacle with the leading limb. Dr. Draganich has completed the construction of an apparatus to aid investigating the effects of disease, drugs or interventions on the ability of a person to step over an obstacle that is suddenly recognized. He has completed preliminary studies investigating the effects of painful KOA and TKA on the rates of successful obstacle avoidance. KOA patients had a 37% lower obstacle avoidance success rate and a 54% lower single leg stance duration (i.e., balance) than did healthy age-matched control subjects, suggesting that individuals with painful KOA have an increased propensity to trip and fall. TKA patients with excellent clinical results and no pain in their lower extremities had a 47% lower obstacle avoidance success rate and a 74% lower single leg stance duration than did the healthy age-matched control subjects, suggesting that TKA patients with excellent clinical results have an increased propensity to trip and fall. Dr. Draganich is currently performing studies to determine if the Knee Society or Hospital For Special Surgery knee rating scores can be used to predict which TKA patients have a higher propensity to avoid stepping on a suddenly recognized obstacle. Approximately 10% of deaths from falls occur on stairs. Thus, Dr. Draganich is also currently investigating the effects of TKA on foot-step clearance during stair stepping. In addition, he is studying the effects of comorbidities in KOA, including quadriceps strength (reduced in KOA), varus angulation (increased in people with medial compartment KOA) and knee laxity (abnormal in KOA) on obstacle avoidance success. Furthermore, Dr. Draganich is expanding his studies of obstacle avoidance to include people with hip osteoarthritis and total hip arthroplasty.

    In collaboration, Dr. Draganich and Dr. Bruce Reider are currently performing a study funded by dj Orthopedics to investigate the effects of off-the-shelf and custom valgus braces on gait, stair-climbing and pain in sports-active patients with painful medial compartment osteoarthritis.

    In collaboration, Dr. Draganich and Dr. Brian Toolan are currently performing a study to investigate the effects of off-the-shelf orthoses and physical therapy on the gait and stair stepping of patients with acquired flatfoot deformity.

 

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Last update: 
January 10, 2010