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Herman van Werkhoven and Stephen J. Piazza

have found the mass-specific metabolic cost of treadmill running to correlate positively and significantly with heel length. Scholz et al 4 suggested a theoretical model that explained how short heels might improve running economy (reduce metabolic cost). Producing the same plantar flexor moment

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Frank E. DiLiberto and Deborah A. Nawoczenski

the external load between the ankle and the ground during forward propulsion. Midfoot region power may also be required to balance the external load across the foot during a single-limb heel rise. Instrumented analysis of heel rise has traditionally focused on the connection between heel height

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Jonathan S. Goodwin, Robert A. Creighton, Brian G. Pietrosimone, Jeffery T. Spang and J. Troy Blackburn

potential to support the use of medial knee unloader braces and/or lateral heel wedges to reduce medial knee compartment loading following traumatic cartilage injury and surgical repair, thus improving cartilage healing. Methods Participants Twenty-two healthy subjects (9 males and 13 females; height: 1

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Piaolin Peng, Shaolan Ding, Zhikang Wang, Yifan Zhang and Jiahao Pan

Shore C), medium (53 Shore C), soft (45 Shore C), and extremely soft (35 Shore C) midsole compositions in the heel area. 16 Consequently, only the peak of the in-shoe force was significantly greater in the extremely hard shoe compared with the other midsoles during touchdown. These contrasting results

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Diego Alonso-Fernandez, Yaiza Taboada-Iglesias, Tania García-Remeseiro and Águeda Gutiérrez-Sánchez

today among amateur athletes. Within the functional eccentric exercises for this muscle group, the most commonly known and used is the heel drop exercise (HDE). This exercise was created to modulate eccentric stimuli on the muscle-tendon complex of the triceps surae, enhancing the muscle performance and

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Sharon J. Dixon and David G. Kerwin

This study investigated the influence of heel lift interventions on the loading of the Achilles tendon for heel-toe runners. It was hypothesized that the peak Achilles tendon force and peak rate of loading would be reduced by the increase in heel lift, and that the peak Achilles tendon force would occur significantly later in stance. Achilles tendon forces were determined by calculating sagittal-plane ankle joint moments using inverse-dynamics techniques and dividing these moments by Achilles tendon moment arm lengths. Methods for estimating Achilles tendon moment arm length using skin markers were justified via MRI data for one participant. Seven participants underwent running trials under three heel lift conditions: zero, 7.5-mm, and 15-mm heel lift. Average magnitude and occurrence time of peak Achilles tendon force and peak rate of loading were determined for each condition over the 7 participants. Despite group reductions in peak Achilles tendon force and peak rate of loading for the increased heel lift conditions, statistical analysis (ANOVA) revealed no significant differences for these variables, p > 0.05. Individual participant observations highlighted varied responses to heel lift; both increases and decreases in peak Achilles tendon force were observed. For the group data, the time of peak impact force occurred significantly later in the 15-mm heel lift condition than in the zero heel lift, p < 0.05. It is suggested that the success of increased heel lift in treating Achilles tendon injury may be due to a later occurrence of peak Achilles tendon force in response to this intervention, reducing Achilles tendon average rate of loading. In addition, the individuality of Achilles tendon peak force changes with heel lift intervention highlights the need for individual participant analysis.

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Sean P. Flanagan, Joo-Eun Song, Man-Ying Wang, Gail A. Greendale, Stanley P. Azen and George J. Salem

The purpose of this investigation was to determine whether increases in internal (muscular) demand would be proportional to increases in the external demand during heel-raise exercise. Seven male (mean age 74.9 ± 4.8 years) and 9 female (mean age 74.4 ± 5.1 years) older adults performed both double-leg heel raises and single-leg heel raises under 3 loading conditions (no external resistance and +5% and +10% of each participant’s body weight). Kinematic and kinetic dependent variables were calculated using standard inverse-dynamics techniques. The results suggest that although the single-heel raise led to increases in peak net joint moments, power, and mechanical-energy expenditure (MEE), it did so at the expense of range of motion and angular velocity. In addition, increasing the external resistance by 5% of participants’ body weight did not elicit significant changes in either the power or the MEE of the ankle joint. These effects should be considered when prescribing these exercises to older adults.

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Michael D. Ross and Elizabeth G. Fontenot

Context:

The standing heel-rise test has been recommended as a means of assessing calf-muscle performance. To the authors' knowledge, the reliability of the test using intraclass correlation coefficients (ICCs) has not been reported.

Objective:

To determine the test-retest reliability of the standing heel-rise test.

Design:

Single-group repeated measures.

Participants:

Seventeen healthy subjects.

Settings and Infevention:

Each subject was asked to perform as many standing heel raises as possible during 2 testing sessions separated by 7 days.

Main Outcome Measures:

Reliability data for the standing heel-rise test were studied through a repeated-measures analysis of variance, ICC2, 1 and SEMs.

Results:

The ICC2,1 and SEM values for the standing heel-rise test were .96 and 2.07 repetitions, respectively.

Conclusions:

The standing heel-rise test offers clinicians a reliable assessment of calfmuscle performance. Further study is necessary to determine the ability of the standing heel-rise test to detect functional deficiencies in patients recovering from lower leg injury or surgery

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Ji-Hyun Lee and Tae-Lim Yoon

motion (ROM) during jogging. 18 Previous studies also demonstrated that reduced ankle dorsiflexion ROM is linked to a high risk of CAI. 19 , 20 To improve ankle dorsiflexion ROM, the present study used the standing heel raise-lower exercise (a heel raise is primarily a concentric plantar flexor

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Benno M. Nigg and H. Alexander Bahlsen

The purpose of this study was to determine the influence of lateral heel flare on pronation, external impact forces, and takeoff supination for different midsole constructions. Data were collected using force platforms and high-speed film cameras. Fourteen male subjects participated in the study, running heel-toe at a speed of 4 m/s. The analysis of kinetic and kinematic variables showed that changes in lateral heel flare of 16°, 0°, and a rounded heel can be used to influence initial pronation during heel-toe running. It could be shown that changes in lateral heel flare do not have a relevant influence on changes in total and/or maximal pronation. Changes in lateral heel flare do have an effect on vertical impact force peaks if the midsole is relatively hard but not if the midsole is relatively soft. Based on the present study, a running shoe with a relatively hard midsole material and a neutral flare would have low initial pronation values and low vertical impact force peaks.