Brazilian Journal of Motor Behavior

Editorial: Effects of aging on locomotor patterns

Paulo C. R. Santos — 2022-12-15

Aging and age-associated neurological diseases, such as Alzheimer's disease and Parkinson's disease, may impair walking performance. Changes in walking performance are related to an increase in fall risk, institutionalization, hospitalization, survival rate, and mortality. Due to the increase in the older population, especially age-related diseases, the number of research aiming at understanding the mechanisms behind such changes and tools (interventions) to improve walking performance has increased substantially. In this special issue, we target to compile information and strengthen the discussion about whether and how aging and AD, and PD affect walking (the most common way of human locomotion), and potential interventions to improve walking in these populations. A total of 5 studies composed this special issue, including 4 original papers and 1 review

Mechanisms that stabilize human walking

Moira van Leeuwen — 2022-12-15

In this paper we review what mechanisms are used to stabilize human bipedal gait. Based on mechanical reasoning, potential mechanisms to control the body center of mass trajectory are modulation of foot placement, stance leg control consisting of modulation of ankle moments and push-off forces, and modulations of the body’s angular momentum. The first two mechanisms and especially the first are dominant in controlling center of mass accelerations during gait, while angular momentum control plays a lesser role, but may be important to control body alignment and orientation. The same control mechanisms stabilize both steady-state and perturbed gait in both the mediolateral and antero-posterior directions. Control is at least in part active and is affected by proprioceptive, visual and vestibular information. Results support that this reflects a feedback process in which sensory information is used to obtain an estimate of the center of mass state based on which foot placement and ankle moments are modulated. These active feedback mechanisms suggest training approaches for populations at risk of falling, such as augmenting their effective use by means of augmented feedback, or using their complementary nature to train one mechanism by constraining the other mechanisms.

Dual-task performance in seniors with mild cognitive impairment and Alzheimer’s disease: a longitudinal study

Danielle C. P. S. Silva — 2022-12-15

BACKGROUND: Motor performance in older adults with cognitive impairment is worse under dual task conditions, increasing the risk of falls. However, there is a lack of studies that analyze this performance over time in people with different cognitive profiles.

AIM: This study aimed to compare the performance of an isolated task and a dual task in people with preserved cognition (PrC), mild cognitive impairment (MCI) and Alzheimer`s disease (AD).

METHOD: Data were collected on two occasions (T1; T2), thirty-two months apart. Participants (n=51) were separated between groups: PrC (n=22), MCI (n=19) and AD (n=10). They were analyzed in three situations: 1) isolated motor task - Timed up and go test (TUGT); 2) cognitive-motor test (CMT)– dialing on the phone; 3) dual task (DT). To compare the performance of the dual task between the groups, delta was calculated and the ANCOVA test was applied.

RESULTS: Although the cost of the dual task was not significantly different over time in any group, we found increases in the time required to complete the TUGT (p<0.01) and TUGT-DT (p>0.01) after 32 months in the AD group and a reduction in time in the PrC and MCI groups. A greater number of steps in the TUGT-DT (p<0.01) and an increase in cadence in the TUGT (p=0.01) and TUGT-DT (p<0.01) were also found in the AD group.

CONCLUSION:We suggest that a more functional task, such as walking while typing on the phone, may be considered a more sensitive way of assessing older adults with AD.

Gait velocity and stability are correlated to muscle and bone mass loss in people with Parkinson’s disease: a preliminary study

Fabio A. Barbieri — 2022-12-15

Background: Parkinson’s disease (PD) exacerbates muscle and bone mass loss, which is associated with several negative outcomes such as falls and disability. Thus, muscle and bone mass loss may be one mechanism for the mediator role between gait impairments and PD. Aim: To verify the relationship between the spatial-temporal gait parameters and the body composition of the lower limbs in people with PD. Method: Thirteen people with PD were evaluated on two different days: i) clinical and gait evaluation; ii) body composition evaluation. The step length, width, duration and speed, the percentage in double support, and gait velocity during walking at self-selected velocity. Dual-energy X-ray absorptiometry technique was used to measure fat mass, lean mass, bone mass, and the total mass, for whole body, and separately for each limb. Pearson’s correlation coefficients were applied between the spatial-temporal gait parameters and the variables of body composition of lower limbs. Results: Reduced lean and bone mass of both legs were related to faster gait velocity (r=0.6, p<0.03 and r=0.7, p<0.01, respectively) and step speed (r=0.5, p<0.05 and r=0.65, p<0.02, respectively). Also, narrower step width was related to the higher bone mass of both legs (r=0.6, p<0.03). However, muscle and bone mass did not correlate with step length and duration, and percentage of double support. Interpretation:Our findings suggest that the muscle and bone mass of the lower limbs are important body characteristics for gait impairments in people with PD and should be monitored over the disease.

Walking speed does not affect age-differences in ankle muscle beta-band intermuscular coherence during treadmill walking

Paulo C. R. Santos — 2022-12-15

Background: By examining whether age and speed each differently affects beta-coherence during walking, we can extend the limited evidence on age-related impairment in neural control of walking. We determined the effects of age and walking speed on intermuscular beta band coherence between lower limb muscle pairs and the association between stride characteristics and intermuscular beta band coherence between these muscle pairs.

Methods: Older (n=12) and younger (n=14) individuals walked on a treadmill at fixed (1.2 m/s) and fast (~1.3x preferred) speeds for 3min. For 100 dominant leg strides, we measured length, width, stance, swing time, cadence and intermuscular beta-coherence (15-35Hz) for the synergistic (biceps femoris (BF)-semitendinosus, rectus femoris (RF)-vastus lateralis (VL), gastrocnemius lateralis (GL)-soleus (SL), Tibialis anterior (TA)-peroneus longus (PL)) and the antagonistic (RF-BF and TA-GL) muscle pairs at swing and stance.

Results: Comparing fast vs. fixed speed, participants walked with increased length (21%), cadence (12%), and coefficient of variation (CV) of stride length (14%), decreased stride width (-20%), and stance (-5%) and swing time (-14%) and with stronger TA-GL beta-coherence during early stance (69%, all p<0.01). Older vs. Younger individuals walked with slower fast gait speed (~9%), higher CV of stride length (21%), weaker GL-SL (-47%) and TA-PL (-60%) beta-coherences during the late swing and early stance phase, respectively (all p<0.01). No Group*Condition interactions occurred

Conclusion: Oscillatory coupling between synergistic ankle muscle pairs during walking is lower in older vs. young individuals, but this difference is independent of walking speed while walking on a treadmill.

Inadvertent obstacle contacts when older adults step over obstacles: Effect of sex, self-reported fatigue, gait parameters, and prescription medications

Timothy Becker — 2022-12-15

Background: Tripping is a common cause of falls, but the factors that are associated with trip risk are understudied.

Aim: To quantify inadvertent trips with a stationary, visible obstacle in older adults, and to determine how inadvertent trips are related to fatigue, sex, gait measures, and prescription medications.

Methods: Forty-one subjects walked on a 6 m walkway and stepped over a visible, stationary obstacle (height: 25% of leg length) 100 times; inadvertent trips with the obstacle were documented. We also collected gait measures on a clear walkway, self-reported fatigue every 25 obstacle crossing trials, and number of prescription medications. Participants were categorized as: 0 contacts or ≥1 contact.

Results: The obstacle was contacted by 15 participants (37%) in 29 trials (0.7% of all trials); 52% of contacts were with the lead limb. Self-reported fatigue increased during the obstacle crossing protocol (p<0.001). Participants in the ≥1 contact group had slower gait speed, shorter stride length, and higher gait cycle time variability (p≤0.041). They also reported higher maximum fatigue (p=0.022) and a higher number of prescription medications (p=0.019). Males and females were not different in contact frequency (p=0.93).

Interpretation: Inadvertent trips were not uncommon in older adults, even with a visible, stationary obstacle. Lead limb contacts indicate that older adults will have more difficulty recovering their balance after a trip. The strong association between fatigue (induced by walking) and impaired gait is highly relevant when quantifying gait in older adults, and also when developing fall prevention programs.

Quiet eye training alleviates the yips in golf putting: a research proposal

Joan N. Vickers — 2022-12-15

A case study is presented of a professional golfer (AB) who in her 13^th LPGA season suffered from the psychological form of the YIPS. She had increased anxiety about her technique and eye movements that made focusing difficult. After a quiet eye (QE) training program she overcame the YIPS and had her 2^nd best season. However, her improvement was temporary for reasons that may have been due to how the treatment was delivered. Due to the pandemic, she was given a QE training program that used email, phone calls, videos showing the quiet eye of elite golfers, counseling, and research papers. Her QE and coupled stroke kinematics were not recorded, as normally occurs, thus the paper concludes with suggestions for a QE training program that may lead to permanent improvements in golf or other sports where this stressful disorder occurs.

Proactive control to navigate our daily environments

Bradford McFadyen — 2022-12-15

Safely navigating our environment is crucial to daily living, but the study of locomotor navigational control in relation to the complex interaction of personal and environmental factors is still in its infancy. Work to now has proposed different proactive control variables for collision avoidance based on visual information. Such control has more recently been shown to be specific to personal (e.g., age, neurological diseases) and environmental (e.g., obstacle type) characteristics. Continued study of the complex person-environment interaction is required along with continued theorization on combined proactive and reactive control factors.

The trajectory of Lilian Teresa Bucken Gobbi (1956-2022): An eminent researcher of gait and posture

Renato Moraes — 2022-12-15