title: Abnormal joint powers before and after the onset of claudication symptoms.
abstract: OBJECTIVE
  Claudication is the most common manifestation of peripheral arterial disease, producing significant ambulatory compromise. Our study evaluated patients with bilateral lower limb claudication and characterized their gait abnormality based on advanced biomechanical analysis using joint torques and powers.
  
  
  METHODS
  Twenty patients with bilateral claudication (10 with isolated aortoiliac disease and 10 with combined aortoiliac and femoropopliteal disease) and 16 matched controls ambulated on a walkway while 3-dimensional biomechanical data were collected. Patients walked before and after onset of claudication pain. Joint torques and powers at early, mid, and late stance for the hip, knee, and ankle joints were calculated for claudicating patients before and after the onset of claudication pain and were compared to controls.
  
  
  RESULTS
  Claudicating patients exhibited significantly reduced hip and knee power at early stance (weight-acceptance phase) due to decreased torques produced by the hip and knee extensors. In mid stance (single-limb support phase), patients had significantly reduced knee and hip power due to the decreased torques produced by the knee extensors and the hip flexors. In late stance (propulsion phase), reduced propulsion was noted with significant reduction in ankle plantar flexor torques and power. These differences were present before and after the onset of pain, with certain parameters worsening in association with pain.
  
  
  CONCLUSIONS
  The gait of claudication is characterized by failure of specific and identifiable muscle groups needed to perform normal walking (weight acceptance, single-limb support, and propulsion). Parameters of gait are abnormal with the first steps taken, in the absence of pain, and certain of these parameters worsen after the onset of claudication pain.
authors.affiliation: Nebraska Biomechanics Core Facility, University of Nebraska at Omaha, Neb, USA.
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Koutakis
authors.forename: Jason M
authors.initials: JM
authors.lastname: Johanning
authors.forename: Gleb R
authors.initials: GR
authors.lastname: Haynatzki
authors.forename: Sara A
authors.initials: SA
authors.lastname: Myers
authors.forename: Nicholas
authors.initials: N
authors.lastname: Stergiou
authors.forename: G Matthew
authors.initials: GM
authors.lastname: Longo
authors.forename: Iraklis I
authors.initials: II
authors.lastname: Pipinos
mesh_terms: D000368:Aged; D000843:Ankle Joint / Q000503:physiopathology; D001157:Arterial Occlusive Diseases / Q000150:complications / Q000503:physiopathology*; D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D005260:Female; D005684:Gait; D006621:Hip Joint / Q000503:physiopathology; D006801:Humans; D007383:Intermittent Claudication / Q000209:etiology / Q000503:physiopathology*; D007484:Iowa; D007596:Joints / Q000503:physiopathology*; D007719:Knee Joint / Q000503:physiopathology; D016014:Linear Models; D035002:Lower Extremity / Q000098:blood supply*; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength; D009329:Nebraska; D010147:Pain Measurement; D016059:Range of Motion, Articular; D012720:Severity of Illness Index; D013997:Time Factors; D019415:Torque; D016474:Weight-Bearing