Antonio’s Recommended Reading, Research, & Review for Human Performance - Issue #11 | June 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: Lower Extremity Muscle Performance and Foot Pressure in Patients Who Have Plantar Fasciitis With and Without Flat Foot Posture

Authors: Lee JH, Shin KH, Jung TS, Jang WY.

Journal: International Journal of Environmental Research and Public Health

Publication Year: 2022

Abstract

Abnormal foot posture and poor muscle performance are potential causes of plantar fasciitis (PF). However, no study has compared the differences between lower extremity muscle performance and foot pressure in patients who have PF with and without abnormal foot postures. This study aimed to compare the differences in lower extremity muscle performance, such as in the hip, quadriceps, hamstring, and plantar flexor, and foot pressure in patients who have PF with and without flat foot postures. Seventy patients with plantar heel pain were enrolled (37 with flat feet and 33 without flat feet). The hip muscle strength was measured using a handheld digital dynamometer. The strength and reaction time of the quadriceps, hamstring, and plantar flexor muscles were evaluated using an isokinetic device. Foot pressure parameters were assessed using pedobarography. The strength of the plantar flexor muscles was significantly lower (p = 0.008).

In contrast, the reaction time of the plantar flexor muscles was considerably faster (p = 0.007) for the involved feet of PF patients with flat feet than those without flat feet. This study confirmed the muscle performance differences between patients with PF and those with different foot postures. Therefore, clinicians and therapists should plan treatment by considering the differences in these characteristics to manage these patients.

Why the Study is Relevant

The study aims to analyze the differences in lower extremity muscle performance and plantar pressure between individuals suffering from plantar fasciitis with and without flat foot posture.

The study design has an acceptable sample size of 70 subjects; however, we can identify a few methodological limitations. There is no mention of how the criteria for exclusion have been met (i.e., how tightness in the gastrocnemius and hamstring muscles is recognized and how leg length differences are measured). No information about the subjects' activity level and lifestyle is provided.

Also, the plantar pressure testing procedure lacks information about the device (i.e., frequency of measurement, resolution), and the protocol, and we don't know if the subject was walking barefoot or shod.

Summary

Plantar fasciitis is one of the most common causes of heel pain, aggravated during walking and running due to microtears of the plantar fascia.

Certain conditions, such as abnormal foot posture, can exacerbate the problem by overstretching the plantar fascia (flat foot) or reducing shock absorption capability (high-arched foot).

The authors of this study investigated the differences in lower extremity muscle strength and foot pressure between patients with plantar fasciitis with and without a flat foot posture to better understand the etiology of plantar fasciitis.

Key Takeaways

• Subjects with plantar fasciitis and flat feet show decreased ankle plantar flexor strength compared to subjects without flat feet.

• The study confirmed the differences in lower extremity muscle strength between subjects with plantar fasciitis and different foot postures.

Read the full study.

Research Title: Plantar Load Distribution With Centers of Gravity Balance and Rearfoot Posture in Daily Lives of Taiwanese College Elite Table Tennis Players: A Cross-Sectional Study

Authors: Chow TH, Lee YL.

Journal: Sports Medicine and Rehabilitation

Publication Year: 2024

Abstract

Background: Table tennis is an asymmetric sport involving the powerful forward swing of the upper limbs depending on the lower limbs' solid support. The foot drive affects the weight balance and stroke accuracy even though the distance and momentum of the lower limb displacement are limited within a limited range. Given that previous research on table tennis has typically focused on the footwork and stroke performance of professional players, the study aimed to investigate the daily static and dynamic plantar load distribution and the centers of gravity balance and rearfoot posture among elite Taiwanese college table tennis players.

Methods: This is a cross-sectional study of 70 elite male table tennis players (age: 20.0 ± 0.9 years; height: 173.4 ± 5.1 cm, weight: 67.6 ± 5.3 kg, experience: 10.0 ± 1.6 years) and 77 amateur table tennis players of the same gender (age: 20.1 ± 0.8 years, height: 167.4 ± 4.4 cm, weight: 64.3 ± 4.0 kg, experience: 4.4 ± 1.2 years) from Taiwanese universities. The JC Mat, an optical plantar pressure analyzer, was applied to determine the plantar load distribution, arch index (AI), and centers of gravity balance. Assessment of rearfoot postural alignment was mainly used to contrast the performance of the centers of gravity balance.

Results: The static AI of both feet in the elite group was symmetrical and considered normal arches (AI: 0.22 ± 0.07) during their non-training and non-competition daily lives. Their static plantar loads were symmetrically concentrated on the bipedal lateral metatarsals (P < 0.05) as well as shifted to the medial and lateral heels (P < 0.05) and the lateral metatarsals (P < 0.05) during the walking midstance phase. Additionally, the plantar loads were mainly applied to the bipedal medial (P < 0.01) and lateral heels (P < 0.05) during the transitional changes between both states. Elite athletes had symmetrical and evenly distributed centers of gravity on both feet (left: 50.03 ± 4.47%; right: 49.97 ± 4.47%) when standing statically, along with symmetrical rearfoot angles and neutral position of the subtalar joint (left: 2.73 ± 2.30°; right: 2.70 ± 2.32°) even though they were statistically lower than those of the amateur athletes (P < 0.05).

Conclusions: The daily static and dynamic foot patterns of the elite Taiwanese college table tennis players were characterized by plantar load distribution on the lateral metatarsals and the entire calcaneus, balanced centers of gravity, and normal rearfoot posture. This foot and posture layout outlines the excellent athletic performance of the foot and ankle in professional athletes.

Why the Study is Relevant

The study aims to investigate the characteristics of plantar load and the centers of gravity balance and rearfoot posture of elite table tennis players.

The design is a cross-sectional study, thus analyzing data at a single point in time.

The study has a good sample size (n=147) divided into two groups: elite players (n=70) and amateur players (n=77). The authors provided very detailed information about the participants' training status and experience.

The equipment being used has a very low sampling frequency (15 Hz), which will negatively affect the quality of the data.

Summary

Table tennis is an asymmetrical sport that requires simultaneous coordination of the hands with the feet and trunk rotation to complete the stroke.

The support and movement of the feet in table tennis affect the stroke's balance and efficiency.

Optimization of foot and ankle movement strategies is thought to be fundamental for energy transfer in the kinetic chain.

The authors of this study tried to investigate the static and dynamic plantar load distribution in elite table tennis players to understand movement behavior and biomechanical strategies better.

Key Takeaways

• Plantar loading, center of gravity balance, and rearfoot posture did not become unilaterally loaded as a result of long-term unilateral movement behavior.

Read the full study.