TLA biofeedback and AGRF biofeedback may improve post-stroke gait through different biomechanical mechanisms
post-stroke
Our comparison between the two modes of biofeedback showed that both TLA biofeedback and AGRF biofeedback increase paretic propulsion. However, TLA biofeedback induced larger increases in TLA than AGRF biofeedback. Somewhat surprisingly, significantly larger increases in TLA caused by TLA biofeedback versus AGRF biofeedback did not translate to larger feedback-induced increases in propulsion. Furthermore, compared to no-biofeedback, AGRF biofeedback effectively increased ankle moment despite participants receiving no specific instructions on increasing ankle moment or force generation as a strategy. In contrast, TLA biofeedback did not increase ankle moment. However, these results about TLA feedback not increasing ankle moment must be interpreted with some caution due to the preliminary nature of the study with a relatively small sample size. The larger TLA-induced increases in TLA may explain the ability of TLA biofeedback to induce similar increases in AGRF as AGRF biofeedback, despite TLA-biofeedback failing to increase ankle moment. Potentially, TLA biofeedback increased AGRF via modulation of overall limb positioning and less so via modulation of ankle-centered kinetics.Future studies will require a systematic evaluation of the dose response relationship between TLA feedback and AGRF feedback targets. Such an approach may further enhance our understanding of the inter-relationships between these two variables. Most importantly, irrespective of the type of feedback, individuals post-stroke demonstrated the ability to modulate the targeted variables of the paretic limb without altering the non-paretic limb.