Effect of botulinum toxin injection in the rectus femoris on stiff-knee gait in people with stroke: a prospective observational study

Stoquart GG, Detrembleur C, Palumbo S, Deltombe T, Lejeune TM. Effect of botulinum toxin injection in the rectus femoris on stiff-knee gait in people with stroke: a prospective observational study.

Objective

To study the effect of botulinum toxin type A (BTX-A) injection in the rectus femoris on the decreased knee flexion during the swing phase of gait (stiff-knee gait) in people with stroke.

Design

Intervention study (before-after trial) with an observational design.

Setting

Outpatient rehabilitation clinic and gait laboratory.

Participants

Nineteen chronic hemiparetic adults presenting with stiff-knee gait.

Intervention

Injection of 200U of BTX-A (Botox) into the rectus femoris.

Main Outcome Measures

Before and 2 months after BTX-A rectus femoris injection: Stroke Impairment Assessment Set (SIAS), Duncan-Ely test, and an instrumented gait analysis.

Results

Median SIAS score improved from 53 (range, 36−65) to 57 (range, 42−70) (signed-rank test, P=.005) and the Duncan-Ely score from 3 (range, 1−3) to 1 (range, 0−3) (P<.001). In gait analysis, mean (± standard deviation) maximum knee flexion improved from 26°±13° to 31°±14° during the swing phase (paired t test, P<.001), knee flexion speed at toe-off improved from 82°±63° to 112°±75°/s (P=.009), and knee negative joint power (eccentric muscular contraction) improved from −.27±.23 to −.37±.26W/kg (P<.001). The 4 patients who almost did not flex the knee (<10°) before the BTX-A rectus femoris injection did not improve after the injection. The other 14 patients who flexed the knee more than 10° before the BTX-A rectus femoris injection decreased the walking energy cost from 5.4±1.6 to 4.6±1.3J·kg⁻¹·m⁻¹ (P=.006).

Conclusions

BTX-A rectus femoris injection may be beneficial in patients with a stiff-knee gait after stroke, particularly in patients with some knee flexion (>10°).