Does the weakening of intrinsic foot muscles cause the decrease of medial longitudinal arch height?

Okamura, Kazunori; Kanai, Setsuko; Oki, Sadaaki; Tanaka, Satoshi; Hirata, Naohisa; Sakamura, Yoshiaki; Idemoto, Norikatsu; Wada, Hiroki; Otsuka, Akihiro

doi:10.1589/jpts.29.1001

Cited by 14 publications

(13 citation statements)

References 19 publications

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“…Doming has been proposed as a rehabilitation exercise to strengthen intrinsic foot muscles, in part because it engages the AH more than toe flexion does (ref 23 here too). However, the extrinsic TA and TP muscles can overpower or overcompensate for weak intrinsic muscles [28], causing an existing muscle imbalance to persist even after doming training. Future studies should focus on training strategies that isolate the AH from the TA and TP.…”

Section: Discussionmentioning

confidence: 99%

Functional assessments of foot strength: a comparative and repeatability study

Bruening

Ridge

Jacobs

et al. 2019

BMC Musculoskelet Disord

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BackgroundEvaluating the strength of the small muscles of the foot may be useful in a variety of clinical applications but is challenging from a methodology standpoint. Previous efforts have focused primarily on the functional movement of toe flexion, but clear methodology guidelines are lacking. A novel foot doming test has also been proposed, but not fully evaluated. The purposes of the present study were to assess the repeatability and comparability of several functional foot strength assessment techniques.MethodsForty healthy volunteers were evaluated across two testing days, with a two-week doming motion practice period between them. Seven different measurements were taken using a custom toe flexion dynamometer (seated), custom doming dynamometer (standing), and a pressure mat (standing). Measurements from the doming dynamometer were evaluated for reliability (ICCs) and a learning effect (paired t-tests), while measurements from the toe flexion dynamometer and pressure mat were evaluated for reliability and comparability (correlations). Electromyography was also used to descriptively assess the extent of muscle isolation in all measurements.ResultsDoming showed excellent within-session reliability (ICCs > 0.944), but a clear learning effect was present, with strength (p < 0.001) and muscle activity increasing between sessions. Both intrinsic and extrinsic muscles were engaged during this test. All toe flexion tests also showed excellent reliability (ICCs > 0.945). Seated toe flexion tests using the dynamometer were moderately correlated to standing toe flexion tests on a pressure mat (r > 0.54); however, there were some differences in muscle activity. The former may better isolate the toe flexors, while the latter appeared to be more functional for many pathologies. On the pressure mat, reciprocal motion appeared to display slightly greater forces and reliability than isolated toe flexion.ConclusionsThis study further refines potential methodology for foot strength testing. These devices and protocols can be duplicated in the clinic to evaluate and monitor rehabilitation progress in clinical populations associated with foot muscle weakness.

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Section: Discussionmentioning

confidence: 99%

Functional assessments of foot strength: a comparative and repeatability study

Bruening

Ridge

Jacobs

et al. 2019

BMC Musculoskelet Disord

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“…We can mention the toe flexor strength with toe-dynamometry (Spink et al, 2010 ) and the paper grip test (De Win et al, 2002 ) and there are several indirect tests assessing the strength or stiffness through the deformation or mobility of the foot arches in weight bearing and non-weight bearing conditions. They are the medial arch height (Okamura et al, 2017 ), the arch rigidity index (Mulligan and Cook, 2013 ), the navicular drop (ND), and the foot mobility measurement (FMM) (McPoil et al, 2009 ), which we will describe in detail.…”

Section: Testing Foot Strengthmentioning

confidence: 99%

“…This assessment performed during gait and/or standing phase requires the use of the Oxford Foot Model, a 3D multi-segment foot model with a good to excellent repeatability (Okamura et al, 2017 ). In this test, the MLA height is defined as the normal distance of the plane of the forefoot from the proximal first metatarsal marker by the Oxford Foot Model.…”

Section: Testing Foot Strengthmentioning

confidence: 99%

How to Evaluate and Improve Foot Strength in Athletes: An Update

Tourillon

Gojanovic²,

Fourchet³

2019

Front. Sports Act. Living

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The foot is a complex system with multiple degrees of freedom that play an essential role in running or sprinting. The intrinsic foot muscles (IFM) are the main local stabilizers of the foot and are part of the active and neural subsystems that constitute the foot core. These muscles lengthen eccentrically during the stance phase of running before shortening at the propulsion phase, as the arch recoils in parallel to the plantar fascia. They play a key role in supporting the medial longitudinal arch, providing flexibility, stability and shock absorption to the foot, whilst partially controlling pronation. Much of the foot rigidity in late stance has been attributed to the windlass mechanism-the dorsiflexion of the toes building tension up in the plantar aponeurosis and stiffening the foot. In addition, recent studies have shown that the IFM provide a necessary active contribution in late stance, in order to develop sufficient impedance in the metatarsal-phalangeal joints. This in turn facilitates the propulsive forces at push-off. These factors support the critical role of the foot in providing rigidity and an efficient lever at push-off. During running or sprinting, athletes need to generate and maintain the highest (linear) running velocity during a single effort in a sprinting lane. Acceleration and sprinting performance requires forces to be transmitted efficiently to the ground. It may be of particular interest to strengthen foot muscles to maintain and improve an optimal capacity to generate and absorb these forces. The current evidence supports multiple exercises to achieve higher strength in the foot, such as the "short foot exercise," doming, toes curl, towing exercises or the more dynamic hopping exercises, or even barefoot running. Their real impact on foot muscle strength remains unclear and data related to its assessment remains scarce, despite a recognized need for this, especially before and after a strengthening intervention. It would be optimal to be able to assess it. In this article, we aim to provide the track and field community with an updated review on the current modalities available for foot strength assessment and training. We present recommendations for the incorporation of foot muscles training for performance and injury prevention in track and field.

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“…Further evidence for this direct anatomical link stems from previous studies in cadaver feet and living young adults [36,42]. These studies showed that, when the foot is fully on the ground and loaded with body weight, foot segment positions are almost constant [42] but PA strain gradually increases with increases in Achilles tendon forces until push-off [36]. We computed therefore total PA strain as the sum of kinematic changes (MTP dorsiflexion angles and calcaneus movement) and increases in Achilles tendon forces.…”

Section: Limitationsmentioning

confidence: 95%

“…The PA is anatomically connected to the paratenon of the Achilles tendon through the periosteum of the heel [12]. Further evidence for this direct anatomical link stems from previous studies in cadaver feet and living young adults [36,42]. These studies showed that, when the foot is fully on the ground and loaded with body weight, foot segment positions are almost constant [42] but PA strain gradually increases with increases in Achilles tendon forces until push-off [36].…”

Section: Limitationsmentioning

confidence: 99%

Biomechanical effects of rocker shoes on plantar aponeurosis strain in patients with plantar fasciitis and healthy controls

et al. 2019

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Plantar fasciitis is a frequently occurring overuse injury of the foot. Shoes with a stiff rocker profile are a commonly prescribed treatment modality used to alleviate complaints associated with plantar fasciitis. In rocker shoes the apex position was moved proximally as compared to normal shoes, limiting the progression of the ground reaction forces (GRF) and peak plantarflexion moments during gait. A stiff sole minimizes dorsiflexion of the toes. The aim of this study was to investigate whether the biomechanical effects of rocker shoes lead to minimization of plantar aponeurosis (PA) strain during gait in patients with plantar fasciitis and in healthy young adults. 8 patients with plantar fasciitis (1 male, 7 females; mean age 55.0 ± 8.4 years) and 8 healthy young adults (8 females; mean age 24.1 ± 1.6 years) participated in the study. Each participant walked for 1 minute on an instrumented treadmill while wearing consecutively in random order shoes with a normal apex position (61.2 ± 2.8% apex) with flexible insole (FN), normal apex position with stiff insole (SN), proximal apex position (56.1 ± 2.6% apex) with flexible insole (FR) and proximal apex position with stiff insole (SR). Marker position data of the foot and lower leg and GRF were recorded. An OpenSim foot model was used to compute the change in PA length based on changes in foot segment positions during gait. The changes in PA length due to increases in Achilles tendon forces were computed based on previous data of a cadaver study. PA strain computed from both methods was not statistically different between shoe conditions. Peak Achilles tendon force, peak first metatarsophalangeal (MTP1) joint angle and peak plantarflexion moment were significantly lower when walking with the rocker shoe with a proximal apex position and a stiff insole for all subjects (p<.05). Changes in Achilles tendon forces during gait accounted for 65 ± 2% of the total PA strain. Rocker shoes with a stiff insole reduce peak dorsiflexion angles of the toes and plantar flexion moments, but not PA strain because the effects of a proximal apex position and stiff insole do not occur at the same time, but independently affect PA strain at 80–90% and 90–100% of the stance phase. Rocker shoes with an apex position of ~56% are insufficient to significantly reduce peak PA strain values in patients with plantar fasciitis and healthy young adults.

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Does the weakening of intrinsic foot muscles cause the decrease of medial longitudinal arch height?

Cited by 14 publications

References 19 publications

Functional assessments of foot strength: a comparative and repeatability study

Functional assessments of foot strength: a comparative and repeatability study

How to Evaluate and Improve Foot Strength in Athletes: An Update

Biomechanical effects of rocker shoes on plantar aponeurosis strain in patients with plantar fasciitis and healthy controls

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