While many outcome measures are available for ambulatory patients, the most commonly cited outcome measures to assess gait speed during exoskeleton use are (Louie 2015):
- 10 Meter Walk Test (10 MWT)
- 2 Minute Walk Test (2 MWT)
- 6 Minute Walk Test (6 MWT)
Additional information on the above listed outcome measures may be found on the Rehabilitation Measures Database. This blog will highlight the 10 MWT and its use with Indego.
What is the 10 Meter Walk Test (10 MWT)?
The 10 MWT is a fast, free, easy to administer test, and has been “highly recommended” by the Academy of Neurological PT’s Spinal Cord Injury Taskforce (SCI EDGE) and Stroke Taskforce (StrokEDGE) for patients across all acuity levels. Reliability, validity, responsiveness, and normative data for the 10 MWT may all be found on the Rehabilitation Measures Database Website.
You may choose to perform the 10 MWT using Indego for many different reasons, including:
- To provide objective documentation that is reflective of a person’s proficiency using Indego.
- To determine if a person would be fast enough to safely cross a street with a support person.
- To document progress along the continuum of training, which may or may not justify continued Indego sessions.
For some patients with preserved lower extremity function who can walk outside of Indego, it may be more appropriate to conduct the 10 MWT before and after Indego use to determine the training effects. In this case, the 10 MWT can be performed using the standard timing method.
The 10 MWT is typically performed either at a self-selected (preferred) walking speed or at a fast walking speed. The Indego Specialists should determine the desired 10 MWT speed and clearly communicate this before beginning the test. Whatever speed you choose for your patient must remain consistent pre-and post- to allow for equal comparisons.
Many studies utilize different methods of conducting the 10 MWT (Lam 2008). For example, some investigators calculate the time required to walk over a full 10-meter walkway (Thomas 2005), while others factor in distance for acceleration and deceleration, measuring only the middle 6 meters (Wirz 2005). Van Hedel et al. cite a 10 MWT using a “flying start”, where the patient walks 14 meters and is timed over the middle 10 meters (Van Hedel 2006). To minimize the impact of any variation between Indego first steps, subsequent steps and steps to slow down and stop walking, the Van Hedel method will be used for 10 MWTs with Indego. The patient will walk a total of 14 meters, with only the middle 10 meters being timed.
Where can I find the 10 MWT in the Indego App?
When you are ready for your patient to complete the 10 MWT, you must first access the 10 MWT in the Indego app. To access the Indego 10 MWT, you must have the most up-to-date version of the Indego app and you must be actively connected to an Indego.
From the Dashboard screen, press the “Test” button at the bottom right hand corner of the screen (see Picture 1). This function will only be accessible after you have completed 20 steps (10 strides) or more. This allows Indego to establish some baseline data for this patient’s walking pattern, and will allow the patient and Indego Specialist to confirm the appropriateness of the Indego settings.
Once you have pressed the “Test” button, you will enter the 10 MWT screen (see Picture 2). Now you are ready to test!
How do I perform the 10 MWT with Indego?
As described above, 10 MWTs with Indego should be performed over a flat, straight 14-meter track. Only the middle 10 meters will be timed.
The floor should be marked at 0, 2, 12, and 14 meters (see Figure 1 below). The patient will start in a standing position at the 0-meter mark, and will walk in a straight line to the 14-meter mark.
Patient instructions for the 10 MWT (derived from rehabmeasures.org) are provided below:
Self-selected speed: “I will say ready, set, go. When I say go, place yourself into green mode, lean forward, and walk at a comfortable speed until I say stop.”
Fast speed:”I will say ready, set, go. When I say go, place yourself into green mode, lean forward, and walk as fast and as safe as you can until I say stop.”
Once the patient’s lead foot crosses the plane of the 2-meter mark, press the “Test” button on your App screen to begin timing (see Picture 2). Press the “Stop” button on your App screen when the patient’s lead foot crosses the plane of the 12-meter mark to end timing (see Picture 3). It is important to note, the time starts and stops when any part of the patient’s lead foot crosses the plane of the line, NOT when the lead foot achieves initial contact.
When the 10 MWT is complete, all data collected during the test will be calculated and displayed. You must press “Save” in the top right corner of the screen to save the 10 MWT data to the session log for that day (see Pictures 4 and 5).
If the test was interrupted, incomplete, or inaccurate for any reason (i.e. you pressed the “Test” button too early or too late, etc.), you may choose to push the “Reset” button and perform the test again without saving the previous attempt (see Picture 6). Indego will alert you that the test has not been saved to ensure that this “Reset” was not done by mistake.
Multiple 10 MWTs may be performed and saved within one session. Averaging the gait speed obtained during multiple 10 MWT trials can help ensure that the gait speed obtained and reported is not the result of one exceptionally fast or exceptionally slow trial. While Indego does not average these speeds automatically, that can be done manually after the session by reviewing the speeds in the patient’s session logs.
10 MWT Data
In addition to calculating the 10 MWT outcomes (time to complete the 10 MWT (mm:ss) and gait speed (m/s)), Indego also calculates the patient’s average stride length (cm) and step symmetry (%).
Stride length is calculated using the distance from the initial contact on one limb to initial contact on the same limb during sequential steps.
Step symmetry is the difference between the left step length and the right step length. It is depicted as a percentage (%). Zero percent would mean that all steps were symmetrical (i.e. the same length). A percentage on either side would indicate that one step is longer. For example, “R 9%” step symmetry would mean that the right step was 9% longer than the left step.
Stride length and step symmetry data may be used to:
Document progress (i.e. improved step symmetry compared to a previous session)
Provide feedback to the patient regarding his or her walking performance (i.e. your strides were shorter this session than last session…try taking longer steps next time)
Make decisions related to the most appropriate iPod settings for this patient
Outcome measures are a common part of any clinician’s practice. Insurance companies often request objective data to justify continued therapy sessions, and Indego’s 10 MWT makes it easy to administer, record, and save outcomes during Indego use. These outcomes may be used for many different reasons, including objectively documenting the patient’s progress.
This article was contributed by Casey Kandilakis, PT, DPT, NCS. Casey is a clinical research scientist at Shepherd Center in Atlanta, Georgia. Casey received her Bachelor of Science in Exercise Science from the University of Tennessee in 2007, and her Doctorate of Physical Therapy from East Tennessee State University in 2010. Since that time, Casey has worked in the field of neurological rehabilitation and research, and has lectured at numerous national and international conferences on the use of advanced technologies in rehabilitation and the translation of research into feasible clinical practice. She became a certified neurologic clinical specialist (NCS) in 2014. Her current research focuses on the use of advanced technologies and exoskeletons with individuals who have lower extremity deficits due to neurological injury or disease. Additionally, Casey is a Certified Indego Instructor, and has taught and lectured about Indego to clinicians around the world.
Shepherd Center, located in Atlanta, Georgia, is a 152 bed, private, not-for-profit hospital specializing in medical treatment, research and rehabilitation for people with spinal cord injury, brain injury and multiple sclerosis.
Lam T, Noonan V, Eng JJ, Spinal Cord Injury Research Evidence (SCIRE) Research Team. A Systematic Review of Functional Ambulation Outcome Measures in Spinal Cord Injury. Spinal Cord. April 2008; 46(4): 246-54.
Louie DR, Eng JJ, Lam T, Spinal Cord Injury Research Evidence (SCIRE) Research Team. Gait Speed Using Powered Robotic Exoskeletons after Spinal Cord Injury: a Systematic Review and Correlational Study. Journal of NeuroEngineering and Rehabilitation. 2015; 1d2: 82.
Thomas SL, Gorassini MA. Increases in corticospinal tract function by treadmill training after incomplete spinal cord injury. J Neurophysiol. 2005 Oct; 94(4):2844-55.
Van Hedel HJ, Wirz M, Curt A. Improving Walking Assessment in Subjects with an Incomplete Spinal Cord Injury: Responsiveness. Spinal Cord. June 2006; 44(6): 352-6.
Wirz M, Zemon DH, Rupp R, Scheel A, Colombo G, Dietz V, Hornby TG. Effectiveness of automated locomotor training in patients with chronic incomplete spinal cord injury: a multicenter trial. Arch Phys Med Rehabil. 2005 Apr; 86(4):672-80.