Antonio’s Recommended Reading, Research, & Review for Human Performance - Issue #12 | October 2024

XSENSOR's Sports Performance Science Contributor, Antonio Robustelli, MSc, CSCS (Sports Performance Scientist & Technologist with OmniAthlete Performance Concept), offers 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 complete studies.

Research Title: Selected Plantar Pressure Characteristics Associated with the Skating Performance of National In-Line Speed Skaters

Authors: Wu WL, Hsiu HT, Chu IH, Tsai FH, Liang JM.

Journal: Sports Biomechanics

Publication Year: 2017

Abstract

This study analyzed the specific plantar pressure characteristics during a 300 m time-trial test to help coaches analyze the techniques of professional in-line speed skaters for making the required fine adjustments and corrections in their push-off work. Fourteen elite in-line speed skaters from the national team were recruited for this study. The total completion time of the 300-m time-trial test, duration of each skating phase, and plantar pressure distribution were measured.

The correlation between plantar pressure distribution and skating performance was assessed using Pearson correlation analyses. The results showed that the contact time of the total foot and force–time integral (FTI) in the medial forefoot were significantly correlated with the duration of the start phase. The FTIs in the medial forefoot of the gliding (left) leg and lateral forefoot of the pushing (right) leg were significantly correlated with the duration of the turning phase.

The maximum force in the medial heel, medial forefoot, and median forefoot and the FTI in the medial heel and medial forefoot were significantly correlated with the duration of the linear acceleration phase. The results suggest that a correct plantar loading area and push-off strategy can enhance skating performance.

Why the Study is Relevant

The study aimed to determine potential relationships between plantar pressure parameters and skating performance and verify the crucial factors contributing to skating performance in different phases.

The study design has a low sample size (n=14), and the group comprises male and female athletes.

No information is provided regarding the subjects' training status at the time of testing (e.g., recovery status, previous training session, etc.). Also, a stopwatch instead of a timing gates system has been used to measure the duration of the time-trial test, which can affect the reliability of the measurement.

However, the question addressed in this study can help us better understand the biomechanics of skating performance.

Summary

In-line speed skating is a competitive form of roller skating in which the competitors race each other by traveling a certain distance on skates.

No studies to date have determined the potential relationships between performance data and plantar loading.

Thus, the authors of this study tried to determine plantar pressure patterns during the start, linear acceleration, and turning phases to help coaches analyze the techniques of professional in-line speed skaters.

Key Takeaways

• Plantar loading may influence skating performance.

• Skaters would create high propulsive force or impulse to improve speed.

• The completion time of the start, turning, and acceleration phases was correlated with the pressure difference under the foot.

Read the full study.

Research Title: Plantar Pressure Modifications in Experienced Runners Following an Exhaustive Run

Authors: Bercovitz T, Herman A, Solomonow-Avnon D, Wolf A, Kodesh E.

Journal: Sports Biomechanics

Publication Year: 2022

Abstract

Running-induced fatigue alters foot strike patterns. This study aimed to assess plantar pressure and center of pressure (CoP) trajectory alterations after a 30-minute run at sub-maximal speed in experienced long-distance runners.

Plantar pressure data from 9 experienced heel-to-toe male runners was collected before and after a 30-minute run on a treadmill at a speed 5% above the respiratory compensation point (RCP) of each participant. Significant changes in the plantar pressure map were found post-run, including increased impulses in the first metatarsal head (9.92%, p < 0.001) and hallux areas (16.19%, p < 0.001) and decreased impulses in the fourth and fifth metatarsal heads (4.95%, p < 0.05). The CoP curve showed a medial shift (p < 0.01). The plantar-pressure map and CoP trajectory were altered following a 30-minute exhausting run. These changes may indicate increased stress on joints and tissues when individuals are fatigued and may promote overload injuries.

Why the Study is Relevant

The study aims to quantify alterations in the plantar pressure map and CoP trajectory of inexperienced long-distance runners after a duration and intensity-controlled exhaustive run.

The study design has a very low sample size (n=7), and the description of the runners is missing important information (e.g., what's the experience and training age of the athletes? How has the type of foot strike pattern been determined? Which kind of shoes are they using?).

While the research topic is precious, using a treadmill may not necessarily depict what happens when running on the road or track.

Summary

Distance running has become a popular recreational activity, and the incidence of running-related injuries in habitual runners has increased in recent years, with a prevalence of 24–65%.

High mechanical loads caused by the ground reaction force at foot contact, in addition to running-induced fatigue, which alters foot strike patterns, are risk factors for stress fractures. Running-induced fatigue has also been shown to cause an imbalance in the neuromuscular response of leg muscles, which may further increase injury risk.

The authors of this study tried to investigate the relationship between running-induced fatigue and alterations in plantar pressure distribution and center of pressure trajectory.

Key Takeaways

• A 30-minute exhausting run caused a medial and anterior shift of the plantar pressure map and CoP trajectory curve.

• Fatigue after high-intensity training sessions or races might promote these changes, which increase stress on joints and tissues and may be part of the underlying mechanism for overuse injuries.

Read the full study.

Research Title: Effects of Jump-Rope-Specific Footwear Selection on Lower Extremity Biomechanics

Authors: Yu HB, Li J, Zhang R, Hao WJ, Lin JZ, Tai WH.

Journal: Bioengineering

Publication Year: 2022

Abstract

Footwear is among the most essential equipment in sports to decrease injuries and enhance performance during exercise. This study investigated differences in lower extremity plantar pressure and muscle activations during jump rope activities. Ten participants performed jump rope under two landing conditions with different footwear. A force platform (AMTI, 1000 Hz), a Novel Pedar-X system (Nove, 100 Hz), and a wireless electromyography (EMG) system (Noraxon, 1500 Hz) were used to measure biomechanical parameters during the jump rope exercise. Vertical ground reaction forces (vGRF), plantar pressure, and lower extremity muscle activations were analyzed. A one-leg landing resulted in a significantly greater vGRF and shorter fly time than a two-leg landing (p < 0.05). A significantly higher peak pressure and lesser toe (LT) area pressure were shown with the jumping shoe (all p < 0.05), but lower plantar pressure resulted in the middle foot area (p < 0.05). The EMG results of tibialis anterior (TA) were significantly greater with one-leg landing (all p < 0.05) during the pre and background activity (BGA) phases. The results suggest that plantar pressure distribution should be considered when deciding on footwear during jump rope exercises. Still, care should be taken about recovery after repeated collisions and fatigue—the jumping shoe benefits from decreased plantar pressure sustained during jump rope exercises.

Why the Study is Relevant

The study aims to evaluate the influence of jump rope and running-specific footwear on the plantar pressure and lower extremity EMG of one—and two-leg consecutive single jump rope movements.

The design suffers from a very small sample size (n=10), and the wires and cables of the plantar pressure system can negatively affect the natural movement during jumping.

Summary

Jump rope is highly accessible, enjoyable, and affordable for anyone. Numerous studies have shown that it is beneficial to cardiorespiratory health, strength, agility, coordination, and bone health. However, a study on home exercise equipment-related injuries indicated that the proportion of injuries caused by jump ropes was 26.3%, with most injuries involving the ankle (79.1%). Appropriate shoes may decrease injury risk. Therefore, footwear selection is particularly important in jump rope exercise.

The authors of this study tried to investigate the influence of specific footwear on lower-limb muscle activations and plantar pressure parameters during jump-rope exercise.

Key Takeaways

• The footwear structural design may influence the plantar pressure in the midfoot area.

• Higher TA muscle activation was observed with jumping shoes than with running shoes during jump rope exercises, and this might reveal better rebound of the jumping shoe.

• Jumping shoes causes lower plantar pressure.

Read the full study.