Effect of Dual Tasks on Gait Symmetry After Anterior Cruciate Ligament Reconstruction
Condition: Anterior Cruciate Ligament Injury
MeSH terms: Anterior Cruciate Ligament Injuries
Study type: Interventional

Summary: 
      Individuals who received anterior cruciate ligament (ACL) reconstruction demonstrated lower
      extremity movement asymmetries. The purpose of this study was to determine if psychological
      impairment was a contributor to lower extremity movement asymmetries in walking for
      individuals who received ACL reconstruction.
    

Detailed description: 
      Background: Anterior cruciate ligament (ACL) reconstruction is a commonly surgical procedure
      to restore knee functions after an ACL injury. Lower extremity movement asymmetries were
      found to be predictive of ACL re-injury and knee OA after ACL reconstruction. Although these
      studies indicated that psychological impairments may contribute to patients' movement
      asymmetries after ACL reconstruction surgery, the effect of psychological impairment on lower
      extremity movement asymmetries has not been confirmed yet.

      Methods: Each participant was asked to wear a pair of black spandex shorts. Passive
      reflective markers were placed bilaterally at the anterior superior iliac spine, posterior
      superior iliac spine, lateral thigh, lateral femoral condyle, medial femoral condyle,
      anterior superior shank, anterior inferior shank, lateral malleoli, medial malleoli, heel,
      and first and fifth metatarsophalangeal. The participant was instructed to walk with barefoot
      in two conditions: (1) without cognitive task (single-task condition), and (2) with
      concurrent cognitive task (dual-task condition). In single-task condition, the participant
      walked along a 10-m walkway at self-selected walking speed. In dual-task condition, the
      participant walked along the walkway while backward counting numbers with an increment of
      seven starting from a randomly given number between 125 and 250. In dual-task condition,
      participants immediately initiated the walking task at their preferred speed once they heard
      the number read by the investigator and kept counting out loudly as required without
      repeating the given number. Participants were asked to count as fast as possible while
      walking task. A 5 min rest was requested between single-task and dual-task test. The order of
      conditions was randomized for the participant. Quadriceps strength was evaluated for the
      participant after walking test.

      Three-dimensional (3-D) trajectories of the reflective markers were collected using an
      8-camera motion capture system (VICON, Oxford, UK) at a sample rate of 100 Hz.
      Ground-reaction force signals were collected using two embedded force plates (AMTI,
      Watertown, Massachusetts) at a sample rate of 1000 Hz. Each participant was asked to have
      three successful trials for each condition. A successful trial was defined as a trial in
      which the participant performed the task as required, and all kinematic and kinetic data were
      collected.

      Quadriceps isometric strength was quantified with an isokinetic dynamometer (CON-TREX MJ;
      Germany) during a maximum voluntary isometric contraction (MVIC). The participant was seated
      with a hip flexed at 90° and knee flexed at 60°. The lateral femoral condyle was aligned with
      the dynamometer axis, and the dynamometer resistance pad was secured to the anterior aspect
      of the distal shank. After correcting for leg weight, the participant was asked to perform
      submaximal practice to familiarize themselves with the testing apparatus. After
      familiarization of testing apparatus, the participant was asked to have three recorded
      maximum-effort trials (5 seconds in duration, 60 seconds' rest between trials) for each leg
      with uninjured leg tested first.
    

Intervention name(s): command
Intervention type(s): Behavioral
Intervention description(s): The participant was asked to walk along the walkway while backward counting numbers with increment of seven starting from a randomly given number.
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Other
Keywords: anterior cruciate ligament; knee; biomechanics; walking; cognition