Comprehensive quantitative investigation of arm swing during walking at various speed and surface slope conditions

Previous studies have shown that inclusion of arm swing in gait rehabilitation leads to more effective walking recovery in patients with walking impairments. However, little is known about the correct arm-swing trajectories to be used in gait rehabilitation given the fact that changes in walking conditions affect arm-swing patterns. In this paper we present a comprehensive look at the effects of a variety of conditions on arm-swing patterns during walking. The results describe the effects of surface slope, walking speed, and physical characteristics on arm-swing patterns in healthy individuals. We propose data-driven mathematical models to describe arm-swing trajectories. Thirty individuals (fifteen females and fifteen males) with a wide range of height (1.58–1.91 m) and body mass (49–98 kg), participated in our study. Based on their self-selected walking speed, each participant performed walking trials with four speeds on five surface slopes while their whole-body kinematics were recorded. Statistical analysis showed that walking speed, surface slope, and height were the major factors influencing arm swing during locomotion. The results demonstrate that data-driven models can successfully describe arm-swing trajectories for normal gait under varying walking conditions. The findings also provide insight into the behavior of the elbow during walking.     

3-D bone models to improve treatment initiation among patients with osteoporosis: A randomised controlled pilot trial

Objective: To investigate the efficacy of 3-D printed bone models as a tool to facilitate initiation of bisphosphonate treatment among individuals who were newly diagnosed with osteoporosis.

Design: Fifty eight participants with estimated fracture risk above that at which guidelines recommend pharmacological intervention were randomised to receive either a standard physician interview or an interview augmented by the presentation of 3-D bone models.

Main outcome measures: Participants’ beliefs about osteoporosis and bisphosphonate treatment, initiation of bisphosphonate therapy assessed at two months using self-report and pharmacy dispensing data.

Results: Individuals in the 3-D bone model intervention condition were more emotionally affected by osteoporosis immediately after the interview (p = .04) and reported a greater understanding of osteoporosis at follow-up (p = .04), than the control group. While a greater proportion of the intervention group initiated an oral bisphosphonate regimen (alendronate) (52%) in comparison with the control group (21%), the overall initiation of medication for osteoporosis, including infusion (zoledronate), did not differ significantly (intervention group 62%, control group 45%, p = .19).

Conclusion: The presentation of 3-D bone models during a medical consultation can modify cognitive and emotional representations relevant to treatment initiation among people with osteoporosis and might facilitate commencement of bisphosphonate treatment.     

The impact of object carriage on independent locomotion

The current study examined whether carrying objects in one's hands influenced different parameters associated with independent locomotion. Specifically, 14- and 24-month-olds walked in a straight path under four conditions of object carriage – no object (control), one object carried in one hand (one object-one hand), two objects carried in each of the hands (two objects-two hands), and one object carried in both hands simultaneously (one object-two hands). Although carrying objects failed to influence a variety of kinematic parameters of gait, it did affect children's arm postures, with children adopting less mature arm positions when carrying objects. Finally, arm position was related to walking skill, but only for older children when they were not carrying objects. These findings indicate that although a relation does exist between arm positions and gait parameters, this relation is easily disrupted by carrying loads, even small ones.     

Effects of experimentally increased trunk stiffness on thorax and pelvis rotations during walking

Patients with non-specific low back pain, or a similar disorder, may stiffen their trunk, which probably alters their walking coordination. To study the direct effects of increasing trunk stiffness, we experimentally increased trunk stiffness during walking, and compared the results with what is known from the literature about gait coordination with, e.g., low back pain. Healthy subjects walked on a treadmill at 3 speeds (0.5, 1.0 and 1.5 m/s), in three conditions (normal, while contracting their abdominal muscles, or wearing an orthopedic brace that limits trunk motions). Kinematics of the legs, thorax and pelvis were recorded, and relative Fourier phases and amplitudes of segment motions were calculated. Increasing trunk stiffness led to a lower thorax–pelvis relative phase, with both a decrease in thorax–leg relative phase, and an increase in pelvis–leg relative phase, as well as reduced rotational amplitude of thorax relative to pelvis. While lower thorax–pelvis relative phase was also found in patients with low back pain, higher pelvis–leg relative phase has never been reported in patients with low back pain or related disorders. These results suggest that increasing trunk stiffness in healthy subjects causes short-term gait coordination changes which are different from those seen in patients with back pain.     

The relationship between hip,knee and ankle muscle mechanical characteristics and gait transition speed

The purpose of the present study was to explore the relationship between mechanical characteristics of hip, knee and ankle extensor and flexor muscle groups and gait transition speed. The sample included 29 physically active male adults homogenized regarding their anthropometric dimensions. Isokinetic and isometric leg muscle mechanical characteristics were assessed by an isokinetic dynamometer, while individual walk-to-run (WRT) and run-to-walk transition speeds (RWT) were determined using the standard increment protocol. The relationship between transition speeds and mechanical variables scaled to body size was determined using Pearson correlation and stepwise linear regression. The highest correlations were found for isokinetic power of ankle dorsal flexors and WRT (r = .468, p < .01) and the power of hip extensors and RWT (r = .442, p < .05). These variables were also the best predictors of WRT and RWT revealing approximately 20% of explained variance. Under the isometric conditions, the maximal force and rate of force development of hip flexors and ankle plantar flexors were moderately related with WRT and RWT (ranged from r = .340 to .427). The only knee muscle mechanical variable that correlated with WRT was low velocity knee flexor torque (r = .366, p < .05). The results generally suggest that the muscle mechanical properties, such as the power of ankle dorsal flexors and hip extensors, influence values of WRT and RWT.