Antonio’s Recommended Reading, Research, & Review for Human Performance - Issue #04 | October 2022

Every month, XSENSOR's Sports Performance Science Contributor, Antonio Robustelli, MSc, CSCS (Sports Performance Scientist & Technologist with OmniAthlete Performance Concept), will offer his take on essential and recommended reading, research, and review for plantar pressure applications using gait analysis for athletes.

Be sure to tune in to get the abstracts, summaries, and key takeaways or read the full studies at your own pace.

Research Title: Correlations between Plantar Pressure & Joint Kinematics in Female Recreational Runners

Authors: Cross JA., Mohamud F., Meinerz C., Harris GF., Dziuk C., Fritz JM.

Journal: Biomedical Sciences Instrumentation

Publication Year: 2021

Abstract

Running provides many health benefits but carries the risk for lower extremity injuries. Previous studies have performed simultaneous assessments of plantar pressure and joint kinematics; however, they have not investigated correlations between these parameters. The goal of this study was to assess relationships between joint kinematics and plantar pressure metrics during stance phase of running. Fifteen female recreational runners participated in this study. Three-dimensional motion analysis and plantar pressure data was collected simultaneously as the subjects ran on an instrumented treadmill. Participants ran at a self-selected speed while maintaining a heart rate (HR) at 70-80% of their maximum HR (max HR = 220 – age). Sagittal and coronal plane motion of the ankle and hip and sagittal plane motion of the knee, along with peak plantar pressure, peak ground reaction force (GRF), force impulse, and pressure impulse were examined. Spearman’s Rho correlation tests were performed to determine correlations among lower extremity joint kinematics and plantar pressure metrics. Positive correlations were found between peak plantar pressure and ankle dorsiflexion, knee flexion, and ankle inversion as well as between running speed and peak GRF. These correlations gave insight into risk factors for injury based on the relationship between plantar pressure metrics and joint kinematics.

Why the Study Is Relevant

This study aims to evaluate the existing relationship between joint kinematics and plantar pressure during the stance phase of running in order to obtain information on potential factors for injury risk.

Although the idea of investigating how plantar pressure and joint kinematics correlate is addressing a very important topic in a sporting activity with a high rate of lower extremity injuries, the study design has several limitations:

1. Sample size is too small to reach a significant statistical power;
2. Treadmill running is not reflecting the complex and chaotic nature of what is happening while running on a track; and
3. No information is available on the training status of the athletes.

Summary

Running is a very common sporting activity with an incidence of lower extremity injuries ranging from 19.3% to 79.3%.

The authors of this study tried to examine the correlations between plantar pressure distribution and joint kinematics in female recreational runners with the goal of improving our understanding of the potential injury risk factors associated with running.

Key Takeaways

• Female recreational runners have significant positive correlations between peak plantar pressure and ankle dorsiflexion, knee flexion, and ankle inversion.
• Plantar pressure may be more indicative of injury risk than GRF.

Research Title: Oscillation of Plantar Pressure Center in Athletes & Non-athletes with & without Ankle Sprains

Authors: Saito AK., Navarro M., Silva MF., Arie EK., Peccin MS.

Journal: Revista Brasileira de Ortopedia

Publication Year: 2016

Abstract

Objective: To assess whether there is any difference in the oscillation of the plantar pressure center in single-leg stance between athletes and non-athletes with and without ankle sprains.

Methods: 54 volunteers performed four static assessments and one dynamic assessment while standing on one foot on a baropodometer, barefoot, for 10 seconds in each test. The variables of area (cm(2)), distance (cm), anteroposterior oscillation (cm), mediolateral oscillation (cm), and mean velocity (cm/s) were analyzed. The items "other symptoms" and "sports and recreation" of the subjective Foot and Ankle Outcome Score (FAOS) questionnaire were applied. For the statistical analysis, repeated-measurement ANOVA (ANOVA-MR), multivariate ANOVA (MANOVA), Tukey's post hoc test and partial eta squared were used.

Results: ANOVA-MR revealed differences regarding distance, with major effects for eyes (p < 0.001), knees (p < 0.001), group (p < 0.05), and the interaction between eyes and knees (p < 0.05); and regarding mean velocity with major effects for eyes (p < 0.001), knees (p < 0.001) (p < 0.05), group (p < 0.05), and the interaction between eyes and knees (p < 0.05). MANOVA revealed main group effects for distance (p < 0.05), anteroposterior oscillation (p < 0.05) and mean velocity (p < 0.05). In the FAOS questionnaire, there were no differences: "other symptoms", p > 0.05; and "sport and recreation", p > 0.05.

Conclusion: Athletes present higher mean velocity of oscillation of plantar pressure center and generally do not have differences in oscillation amplitude in the sagittal and coronal planes, in comparison with non-athletes.

Why the Study Is Relevant

The aim of this study is to evaluate the difference in center of pressure oscillation among athletes and non-athletes with and without ankle sprain.

The design of the study is suffering from a small sample size for both groups as well as a lack of information on training status and other activities performed in the hours before the test that may have influenced the outcome.

Also, no information are present on taking medications or other nutritional factors that may have influenced the test results.

Summary

Postural control and stability are fundamental qualities for athletes competing in court-sports where complex motor tasks can be impaired by injuries that may lead to instability such as ankle sprains.

The authors of the study tried to investigate how an ankle sprain can influence the stability and postural control of athletes by looking at changes in mean velocity of the center of pressure oscillation.

Key Takeaways

• Athletes have higher center of pressure oscillation mean velocity respect to non-athletes.
• No difference in the amplitude of center of pressure oscillation between athletes and non-athletes.
• Athletes without ankle sprain have higher mean velocity of center of pressure oscillation.

Research Title: Effects of Minimalist Footwear & Foot Strike Pattern on Plantar Pressure during a Prolonged Running

Authors: Izquierdo-Renau M., Sanchis-Sanchis R., Priego-Quesada JI., Encarnacion-Martinez A., Queralt A., Perez-Soriano P.

Journal: Applied Sciences

Publication Year: 2022

Abstract

The use of minimalist shoes (MS) in running involves changes in running mechanics compared to conventional shoes (CS), but there is still little research analyzing the effects of this footwear on plantar pressure, which could help to understand some risk injury factors. Moreover, there are no studies examining the effects of a prolonged running and foot strike patterns on baropodometric variables in MS. Therefore, the aim of this study was to analyses the changes produced using MS on plantar pressure during a prolonged running, as well as its interaction with the time and foot strike pattern. Twenty-one experienced minimalist runners (age 38±10 years, MS running experience 2±1 years) ran with MS and CS for 30 min at 80% of their maximal aerobic speed, and mean pressure, peak pressure, contact time, center of pressure velocity, relative force, and contact area were analyzed using a pressure platform. Foot strike pattern and time were also considered as factors. The multivariable linear regression mixed models showed that the use of MS induced, at the end of a prolonged running, higher peak pressure (p = 0.008), lower contact time (p = 0.004) and lower contact area (p < 0.001) than using CS. Also, runners with forefoot strike pattern using MS, compared to midfoot and rearfoot patterns, showed higher mean and peak pressure (p < 0.001) and lower contact time and area (p < 0.05). These results should be considered when planning training for runners using MS, as higher peak pressure values when using this type of footwear could be a risk factor for the development of some foot injuries.

Why the Study Is Relevant

The aim of this study is to evaluate which changes in plantar pressure occurs during prolonged running with the use of minimalist shoes.

The study addresses a very interesting topic in the applied sport science as the use of minimalist shoes has seen a rise in utilization in recent years and results on their efficacy compared to conventional shoes in terms of injury reduction are contradictory.

The research has a crossover design and has its main pros in the very applied nature of the study as the tests have been performed outdoor on a 400 m track to better translate into a real-world scenario. Also, other important aspects such as the training status and volume were added to the inclusion criteria.

The quality of the study would have been improved by having a larger sample size and by using an in-shoe plantar pressure measurement system to better capture the dynamics of the foot strike and plantar pressure distribution.

Summary

The use of minimalist shoes have been shown to change the mechanics of running compared to conventional shoes. In the last decade there has been an increased interest about barefoot and/or minimalist running in the field of sports biomechanics and there are very few studies analyzing the effects of minimalist shoes on plantar pressure during prolonged running.

The authors of this study tried to address this topic by considering other factors such as the foot strike pattern and the previous experience of the runner with minimalist shoes.

Key Takeaways

• Higher plantar pressure during prolonged running with minimalist shoes compared to conventional shoes.
• Minimalist shoes increases mean and peak pressures in forefoot pattern strike compared to midfoot/rearfoot pattern strike.
• Increase in plantar pressure in minimalist shoes with a forefoot pattern should be considered as a potential injury risk factor.

Read the full study.