A walkway system called GAITRite is a reliable and feasible method to assess gait in young patients with Friedreich’s ataxia (FA), according to a new study. FA patients showed slower speed and increased stride time, among other changes.
The study, titled, “Test-retest reliability of an instrumented electronic walkway system (GAITRite) for the measurement of spatio-temporal gait parameters in young patients with Friedreich’s ataxia,” appeared in the journal Gait & Posture.
Symptoms of Friedreich’s ataxia such as loss of coordination, or ataxia, loss of reflexes, and skeletal deformities called scoliosis — curvature of the spine — along with high-arched feet (pes cavus), all affect the ability of FA patients to walk and maintain an upright posture.
Impaired gait in these patients involves deviations of walk trajectory and spatio-temporal (STP) alterations, including reduced stride length and gait velocity. Although various approaches have been used for disease management — including physical therapy, medications, surgery, and orthoses — evidence supporting their effectiveness is scarce.
To fully understand gait impairment in FA patients, specific walking patterns need to be better determined. For this purpose, as well as to assess treatment outcomes, reliable gait monitoring systems are required, the scientists considered.
The portable GAITRite walkway system has been validated in healthy children and adults to analyze gait problems, but no study has assessed the system’s feasibility to assess STP parameters in ataxic, or staggering, gait.
So, the scientists intended to measure the ability to reproduce STP measurements and gait scores in young patients with Friedreich’s ataxia and to describe the characteristics of this type of gait, which is known for its high variability in each patient.
The final analysis included 36 individuals (18 males and 18 females), with mean age of 16.4. Four patients were not able to walk independently, requiring an anterior rollator.
The mean time from initial symptoms of Friedreich’s ataxia was 7.3 years. Thirty-one patients (86%) had early-onset FA, meaning they were younger than 14 when symptoms started. Also, repeat expansion of over 800 GAA triplets, which correlates with disease severity, was observed in 12 patients (33%).
All patients were admitted to the Robert Debré University Hospital in France for three days. They were asked to walk on the GAITRite system barefoot at a self-selected pace. The two who weren’t able to walk barefoot because they wore orthopedic shoes and ankle-foot orthoses remained in the study. Those who toe-walked, a common gait pattern in FA, also continued.
Each patient performed three trials, maintaining a distance better than 10 meters with a minimum of eight strides. A second set of three trials was repeated after 48 hours to evaluate the test-retest reproducibility.
Data processing and analyses were automatically conducted by the software. Two gait scores were calculated.
Speed (cm/s), velocity normalized by leg length (L/s) and cadence — also known as stride rate (step/min) — were collected for each patient. Step and stride length (cm), step and stride time (s), base of support (cm), and foot progression angle were among the collected variables for each lower limb.
Of note, foot progression angle corresponded to the angle between the line of progression and the line connecting the heels to the forward point of the footprint.
Most gait parameters demonstrated high or very high reproducibility, except foot progression angle and base of support, which the team attributed to software errors and weakness in patients’ ankle ligaments.
No measure showed poor or fair reproducibility. All parameters showed low variability between day one and day three.
Compared to individuals with normal gait, Friedreich’s ataxia patients exhibited slower speed (100 vs. 115 cm/s), broadened base of support (12.6 vs. 7 cm), as well as increased step (0.58 vs. 0.51 s) and stride time (1.17 vs. 1 s).
Twenty-four patients showed inconstant forefoot striking at initial contact. Gait scores were significantly lower than those of controls in the study.
“The current study reports the largest number of [FA] patients evaluated for their gait characteristics and proves that the GAITRite system shows a good reliability in this specific type of patient,” the researchers wrote.
They added that having 36 patients able to walk as instructed “demonstrated the feasibility of the GAITRite walkway in young patients with Friedreich’s ataxia.”
Additional studies are required to evaluate the reliability of GAITRite to assess gait changes over time and to determine links with disease severity, they noted.