The influence of heel pad confinement on heel pad mechanical properties

Background: Musculoskeletal foot disorders have a high incidence among overweight and obese individuals. One of the important factors causing this high incidence may be plantar fascia and heel pad (HP)–related mechanical changes occurring in these individuals. The aim of the present study was to investigate the plantar fascia and HP stiffness and thickness parameters in overweight and obese individuals and compare these values with those of normal-weight individuals. Methods: This study was carried out in 87 (52 female, 35 male) healthy sedentary individuals between the ages of 19 and 58 years (34 ± 11 years). Participants were subsequently categorized according to body mass index (BMI) as normal weight (18.5 kg/m2 < BMI < 25 kg/m2) or overweight and obese (BMI ≥25 kg/m2). Plantar fascia and HP thickness and stiffness were measured with an ultrasonography device using a linear ultrasonography probe. Results: Overweight and obese individuals had higher HP thickness ( P < .001), plantar fascia thickness ( P = .001), heel pad microchamber layer (MIC) stiffness ( P < .001), and heel pad macrochamber layer (MAC) stiffness ( P < .001), whereas they had lower plantar fascia stiffness ( P < .001) compared with the individuals with normal weight. BMI had a moderate correlation with HP thickness ( P < .001, r = 0.500), plantar fascia thickness ( P = .001, r = 0.536), MIC stiffness ( P < .001, r = 0.496), and MAC stiffness ( P < .001, r = 0.425). A negative and moderate correlation was found between BMI and plantar fascia stiffness ( P < .001, r = –0.439). Conclusion: Increased BMI causes a decrease in the stiffness of plantar fascia and an increase in the thickness of the plantar fascia as well as the thickness and stiffness of HP. Increased body mass could cause changes in the mechanical properties of HP and plantar fascia. Level of Evidence: Level 3, comparative study.

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The Mechanical Properties of the Heel Pad in Unilateral Plantar Heel Pain Syndrome

Foot & Ankle International ◽

10.1177/107110079902001010 ◽

1999 ◽

Vol 20 (10) ◽

pp. 663-668 ◽

Cited By ~ 21

Author(s):

Wen-Chung Tsai ◽

Chung-Li Wang ◽

Tsz-Ching Hsu ◽

Fon-Jou Hsieh ◽

Fuk-Tan Tang

Keyword(s):

Mechanical Properties ◽

Pain Syndrome ◽

Heel Pain ◽

Plantar Heel Pain ◽

Heel Pad

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Mechanical properties of the heel pad: current theory and review of the literature

The Foot ◽

10.1016/s0958-2592(98)90026-8 ◽

1998 ◽

Vol 8 (4) ◽

pp. 179-185 ◽

Cited By ~ 35

Author(s):

K Rome

Keyword(s):

Mechanical Properties ◽

Current Theory ◽

Review Of The Literature ◽

Heel Pad

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Spatial-Dependent Mechanical Properties of the Heel Pad by Shear Wave Elastography

Ultrasound in Medicine & Biology ◽

10.1016/j.ultrasmedbio.2017.08.1242 ◽

2017 ◽

Vol 43 ◽

pp. S89-S90 ◽

Cited By ~ 1

Author(s):

Chung-Li Wang ◽

Che-Yu Lin ◽

Pei-Yu Chen ◽

Yio-Wha Shau ◽

Hao-chih Tai

Keyword(s):

Mechanical Properties ◽

Shear Wave ◽

Shear Wave Elastography ◽

Heel Pad

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The influence of foot posture, support stiffness, heel pad loading and tissue mechanical properties on biomechanical factors associated with a risk of heel ulceration

Journal of the Mechanical Behavior of Biomedical Materials ◽

10.1016/j.jmbbm.2011.01.004 ◽

2011 ◽

Vol 4 (4) ◽

pp. 572-582 ◽

Cited By ~ 50

Author(s):

Ran Sopher ◽

Jane Nixon ◽

Elizabeth McGinnis ◽

Amit Gefen

Keyword(s):

Mechanical Properties ◽

Factors Associated ◽

Heel Pad ◽

Foot Posture ◽

Biomechanical Factors

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The time-dependent mechanical properties of the human heel pad in the context of locomotion.

Journal of Experimental Biology ◽

10.1242/jeb.199.7.1501 ◽

1996 ◽

Vol 199 (7) ◽

pp. 1501-1508 ◽

Cited By ~ 1

Author(s):

R F Ker

Keyword(s):

Mechanical Properties ◽

Energy Loss ◽

Compressive Loading ◽

Fold Increase ◽

Deformation Curves ◽

Heel Pad ◽

Rest Periods ◽

Percentage Area ◽

Rest Time ◽

Loading And Unloading

Previous measurements of the mechanical properties of the heel pad, especially of the energy loss during a cycle of compressive loading and unloading, have given contrasting values according to whether the investigators used isolated single impacts (e.g. pendulum tests; energy loss approximately 48%) or continuous oscillations (energy loss approximately 30%). To investigate this discrepancy, rest periods were inserted between single compressive cycles, giving intermittent loading as in locomotion. The energy loss, measured as the percentage area of the hysteresis loop, was found to change linearly with the logarithm of the rest time. It was approximately 33% when the rest time was 1 s. Each 10-fold increase in the rest time added approximately 3.7% to the energy loss. Thus, with rest times appropriate to locomotion, the pad is far from fully relaxed. The springy heel pad may help to reposition the foot during the transfer of load from the heel to the forefoot. Information is also included on the load-deformation curves for the heel pad and the way in which these change with rest time. This is presented as equations which may be useful in future models relating the mechanical properties of the heel to either its structure or its function.

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