The effect of unstable shoe designs on the variability of gait measures

Testing the effects of footwear on biomechanics of human body: A review

Studies show the high potential of shoes to impact human movement and reduce the risk of injuries during normal and high-demanding activities. This review will delve into the existing literature on mechanical and biomechanical tests of shoes and their effects on the human body. Mechanical tests mainly include compression, bending, torsional flexibility, and impact tests. Biomechanical tests, on the other hand, study the kinematics and kinetics of the human body while performing different tasks. The primary goal of this review is to highlight the importance of isolating parameters in shoe design and testing to achieve optimal results in providing comfort, support, and injury prevention. Key conclusions include the influence of lattice structures on shoe stiffness and stress distribution, the effectiveness of composite loofah sponge for vibration damping, the benefits of Poron insoles for impact attenuation, the potential injury risk reduction with auxetic shoes, and the need for future research on mechanical tests, parameter investigation, and optimization of shoe sole structures.

Effects of auxetic shoe on lumbar spine kinematics and kinetics during gait and drop vertical jump by a combined in vivo and modeling investigation

The present study examined the effects of auxetic shoes on the biomechanics of the spine, as compared to barefoot and conventional shoe conditions, during gait and drop vertical jump (DVJ) activities using a combined in vivo and musculoskeletal modeling approach. Motion and force-plate data as well as electromyographic (EMG) activities of select trunk muscles of 11 individuals were collected during foregoing activities. In DVJ activity, two main phases of first landing (FL) and second landing (SL) were studied. In the FL phase of DVJ noticeable alternations were observed when auxetic shoes were used. That is, compared to the conventional footwear condition, smaller EMG activities in extensor muscles (by ~ 16-29%, p < 0.001), smaller anterior-posterior (AP) distance between the center of pressure of ground reaction force and heel (by ~ 19%, p = 0.002), generally larger maximal hip, knee, and ankle flexion angles (p < 0.005) and finally smaller maximal L5-S1 compression force and maximal external moment (by ~ 12 and 8%, respectively, p < 0.001) were obtained by wearing auxetic shoes. Our results, therefore, indicate that using auxetic shoes can reduce load on the lumbar spine during high-demanding activities such as vertical jump and thus may decrease the musculoskeletal risk of injuries during these activities.

Avoidance of Total Knee Replacement in a Population Health Setting: Introducing a Noninvasive Biomechanical Intervention for Patients with Knee Osteoarthritis

The observed increase in osteoarthritis (OA) of the knee as a result of an aging population and the obesity epidemic has led to a concomitant increase in the rates of total knee replacement (TKR), placing an additional financial and social burden on the ability of health care systems to control medical costs. Our study shows how a home-based, noninvasive biomechanical intervention reduced the rate of progression to surgery for a cohort of 237 patients with knee OA deemed eligible for TKR based on pre-established clinical selection criteria. Over the 24-month study period, 204 patients (86%) avoided surgery, with only 33 patients (14%, 95% confidence interval 82%-91%) progressing to a TKR with an average length of time to TKR of 324 days (ranging from 31 to 671 days). The application of this intervention provides health plans and provider networks managing patient care under financial risk arrangements an opportunity to realize significant cost savings without compromising quality of care or clinical outcomes.

Walking Speed Alters Barefoot Gait Coordination and Variability

Using the dynamic system approach, we examined the pattern and variability of inter-joint coordination in barefoot and shod walking in 20 women at three speeds: SLOW, FAST, and comfortable walking speed (CWS). We found that barefoot and shod walking used different coordination strategies to cope with increasing walking speed. As walking speed increased, ankle-knee coordination patterns between shod and barefoot became less different (p < 0.00001), and ankle-hip coordination patterns became more different (p < 0.001). Compared to shod, barefoot walking had significantly lower coordination variability in mid stance of knee-hip at CWS and FAST and late swing of ankle-hip at SLOW and CWS with medium effect (effect size 0.61-0.74). Future research should investigate the connection between the decreased coordination variability and joint tissue stress to understand the impact of barefoot walking on the lower extremity joints.

The impact of shod vs unshod walking on center of pressure variability

BACKGROUND

The variability of center of pressure (COP) is a measure of stability commonly examined during quiet standing. While more recent research has examined the variability of COP during walking, an adequate comparison between shod and unshod walking conditions has yet to be made.

RESEARCH QUESTION

What is the influence of athletic footwear on the variability of COP displacement during walking?

METHODS

In this intervention study, twenty healthy women (age 18-30 years) completed 2, 10-min walking trials, 1 shod and 1 unshod, during which ground reaction forces (GRF) and COP movement were collected by an instrumental treadmill. COP displacement was examined in the medial-lateral (ML) and anterior-posterior (AP) directions after being divided into quadrants based on the peaks and trough of each steps associated vertical GRF. A single MANOVA was used to determine effects of footwear and limb for each quadrant with the probability of a Type I error set at 0.05.

RESULTS

Significant differences in variability were seen between footwear conditions in all quadrants in the AP direction and quadrants one and four in the ML direction. These results may be due to the structure of footwear, including midsole cushioning, altering the dynamics of the foot during walking.

SIGNIFICANCE

The results of this study suggest that on average, athletic footwear reduces the variability of COP displacement in ML and AP directions. This may have implications for populations for whom variability of COP is determined to be undesirable.