Table 5.
Brain activity due to mechanical challenges to dynamic balance control.
| Name, year | Balance challenge | TM or OG | Modality | Mobile | Spatial information | Brain activity |
|---|---|---|---|---|---|---|
| Beurskens et al., 2016 | ST vs. DT: Motor or cognitive interference | TM PWS | EEG | Yes | FCz | Alpha band activity decreased during motor DT vs. ST |
| FPz, Fz | Beta increased during motor vs. cognitive DT | |||||
| Bradford et al., 2015 | TM walking at specified levels of incline | TM Fixed | EEG | No | Sensorimotor, posterior parietal, ACC clusters | Higher theta power fluctuations across gait cycle in inclined walking conditions |
| Lt. sensorimotor, ACC clusters | Greater gamma power during level walking | |||||
| Lt. and rt. sensorimotor cluster | Distinct alpha and beta fluctuations dependent on gait cycle for both walking conditions | |||||
| Bruijn et al., 2015 | Laterally stabilized while TM walking | TM Fixed | EEG | No | Bilateral premotor cortices | Higher beta power during stabilized walking in left premotor area specifically around push-off |
| Bulea et al., 2015 | Steady state walking using an active or a passive TM | TM: Fixed vs. feedback driven | EEG | Yes | PFC and posterior parietal cortex | Low gamma band power increased during double support and early swing phases in active TM |
| Sensorimotor cortex | Mu and beta band desynchronization during walking cycle | |||||
| Clark et al., 2014b | Carrying tray, obstacles, and weighted vest tasks while walking in older adults | OG | fNIRS | No | PFC | Increased activation in walking phase |
| Haefeli et al., 2011 | Obstacle navigation in dim lighting with audio cue to signal upcoming obstacle | TM Fixed | EEG | No | Oribital gyrus (BA 11) and medial frontal gyrus (BA 10) | Activation in preparation phase prior to stepping over obstacle |
| Superior frontal gyrus (BA 9) | Activation in performance phase | |||||
| Jaeger et al., 2016 | External load applied during stepping movements | Stepping | fMRI | No | SMA-proper (BA4a), superior occipital gyrus (BA 18) | Activation in 0 load condition |
| Vermis, S1/M1 (left BA 6), Thalamus | Activation in 20 load condition | |||||
| Insula, vermis, middle occipital gyrus, precuneus S2, thalamus, sup occ. gyrus | Activation in 40 load condition | |||||
| Kurz et al., 2012 | Forward vs. backward walking on TM | TM Fixed | fNIRS | No | SMA, pre-central gyrus, sup. parietal lobule | Increased activation in backward walking |
| Pre-central gyrus and SMA | Maximal activation correlated with stride-time intervals in forward walking | |||||
| Lin and Lin, 2016 | Overground walking with wide, narrow, or obstacle path with and without n-back task | OG | fNIRS | No | PFC | Increased activation at beginning of task |
| Lu et al., 2015 | Please refer to Table 6 | |||||
| Maidan et al., 2015 | Walking patterns known to cause FoG in PD patients with FoG and healthy controls | OG | fNIRS | No | Frontal activation (BA 10) | Decreased activation during turns without FoG episode in PD group |
| Increased activation during anticipated turns before and during FoG episode | ||||||
| No changes in activation in controls | ||||||
| Presacco et al., 2011 | Real time visual feedback of lower limbs provided in order to avoid stepping on diagonal stripe on TM belt | TM PWS | EEG | No | Full scalp analysis | Higher delta, theta, and low beta spectral power during walking vs. rest |
| Prefrontal, central, posterior-occipital, right, and left hemisphere regions of interest | Fluctuations in amplitude in EEG signals in low delta frequency band can predict gait kinematics | |||||
| Presacco et al., 2012 | Real time visual feedback of lower limbs provided in order to avoid stepping on diagonal stripe on TM belt | TM PWS | EEG | No | Pre-frontal, motor, parietal, and occipital areas | Standardized voltage level fluctuations over time can predict gait kinematics |
| Sipp et al., 2013 | Heel-to-toe walking on a TM-mounted balance beam | TM Fixed | EEG | No | ACC, anterior parietal, superior DLPFC, medial sensorimotor cortex | Larger mean theta power during walking on balance beam vs. TM |
| Lt. and rt. sensorimotor cortex clusters | Lower beta power during walking on balance beam vs. TM | |||||
| Lt. sensorimotor cortex | Visible indication on spectrogram when falling off beam | |||||
| Varghese et al., 2016 | APA for lateral weight shift or stepping task with/without preloading weight to the stance leg | Stepping | EEG | No | Mid fronto-central electrodes | Increase in amplitude of movement related potentials prior to initiation of postural adjustment |
| Movement related potentials associated with APA onset | ||||||
| ERD of mu and beta bands associated with APA onset | ||||||
TM, treadmill; OG, overground; PW, preferred walking speed; ST, single task; DT, dual task; APA, anticipatory postural adjustment; PD, Parkinson's Disease; FoG, freezing of gait; BA, Brodmann Area; lt., left; rt., right; bi. lat., bilateral; PFC, prefrontal cortex; DLPFC, dorsolateral prefrontal cortex; ACC, anterior cingulate cortex; SMA, supplementary motor area; ERD, event related desynchronization.