Effect of rocker shoe radius on oxygen consumption rate in young able-bodied persons

doi:10.1016/j.jbiomech.2011.02.008

Journal of Biomechanics

Volume 44, Issue 6, 7 April 2011, Pages 1021-1024

https://doi.org/10.1016/j.jbiomech.2011.02.008 Get rights and content

Abstract

We studied oxygen consumption rate of eleven young able-bodied persons walking at self-selected speed with five different pairs of shoes: one regular pair without rocker soles (REG) and four pairs with uniform hardness (35–40 shore A durometer) rocker soles of different radii (25% of leg length (LL) (R25), 40% LL (R40), 55% LL (R55), and infinite radius (FLAT)). Rocker soled shoes in the study were developed to provide similar vertical lift (three inches higher than the REG shoes condition). Oxygen consumption rate was significantly affected by the use of the different shoes (p<0.001) and pairwise comparisons indicated that persons consumed significantly less oxygen (per minute per kilogram of body mass) when walking on the R40 shoes when compared with both the FLAT (p<0.001) and REG (p=0.021) shoe conditions. Oxygen consumption was also significantly less for the R25 shoes compared with the FLAT shoes (p=0.005) and for the R55 shoes compared with FLAT shoes (p=0.027). The three-inch lift on the FLAT shoe did not cause a significant change in oxygen consumption compared to the shoe without the lift (REG).

Introduction

Rocker shoes are used frequently in physical medicine and rehabilitation to treat ailments of the lower limb (see review by Hutchins et al. (2009)). Most studies have focused on the effects of rocker shoes on plantar pressures (Nawoczenski et al., 1988, Schaff and Cavanagh, 1990, Mueller et al., 1997, Postema et al., 1998, van Schie et al., 2000, Praet and Louwerens, 2003, Brown et al., 2004), while others have focused on the effects of rocker shoes on kinematics and kinetics of gait (Peterson et al., 1985, Wu et al., 2004, Van Bogart et al., 2005, Myers et al., 2006, Long et al., 2007). Few investigators have examined the effects of rocker shoes on energetic cost during walking.

Perry et al. (1981) studied the effectiveness of a rocker bottom shoe for restoring walking function for several women with multiple sclerosis. The rocker shoes were found to be beneficial to three women in the study with “obstructive spasticity,” helping them improve their self-selected walking speed from 55% to 103% of able-bodied walking speeds. When switching from normal shoes to rocker shoes, energy cost in this subject group was reduced from 717% to 93% of the cost used by able-bodied persons.

Adamczyk et al. (2006) examined the effects of using rigid rocker boots with immobilized ankles on metabolic rate of able-bodied ambulators. They found that the subjects walked with a minimum metabolic rate when the rocker radius was approximately 0.3 times the leg length compared to other rocker radii. Adamczyk et al. (2006) also found that the metabolic rate was higher with rigid rocker boots (and any of the rockers studied) than normal metabolic rates with unconstrained ankles. The research group later attributed this difference in energy cost to the weight of the boots (Vanderpool et al., 2008) and stated that use of an appropriate rocker shape with an immobilized ankle “need not increase energy expenditure for walking.”

A recent study by van Engelen et al. (2010) compared the metabolic energy cost of able-bodied persons walking with normal walking shoes and MBT rocker bottom shoes and found a higher metabolic energy cost when walking with the MBT shoes. The group postulated that the increase in metabolic cost may be due to the soft heel region of the MBT shoes, which likely caused instability and increased lower limb muscle activity in early stance and which coincided with higher external mechanical work lost in the “collision” phase. The group also cited the increased weight of the MBT shoes compared with the normal shoes as a potential factor leading to increased metabolic energy cost. It is possible that use of rocker bottom shoes with less compliance in the heel could provide different results. Also, no studies to our knowledge have investigated the effects of different rocker shoe radii (with unconstrained ankles) on oxygen consumption during walking.

The purpose of this study was to examine the oxygen consumption of young able-bodied persons walking using a series of rocker shoes with different rocker radii to determine whether certain radii would provide an energetic benefit. The rocker shoes had soles of uniform hardness and density for the heel and forefoot. We also examined the effects associated with adding the weight and height of the rocker soles by including the same shoe type without the addition of the rocker sole in the study.

Section snippets

Methods

Eleven subjects participated in the study (six males and five females). The subjects had an average (standard deviation) age of 28(4) years, height of 176(10) cm, and mass of 71(14) kg. The subjects were primarily graduate students at the Northwestern University.

Subjects first went through a consent process approved by the Northwestern University Institutional Review Board and provided written consent at the end of the process. Ankle strength and passive range of motion (non-weight bearing) were

Results

The shoes significantly affected oxygen consumption rate (p<0.001; see Fig. 2). Pairwise comparisons indicated that less oxygen (per minute per kg of body mass) was consumed when walking with the R40 shoes compared with the FLAT shoes (p<0.001) and also compared with the REG shoes (p=0.021). Oxygen consumption was also reduced when walking with the R25 shoes compared with the FLAT shoes (p=0.005) and when walking with the R55 shoes compared with the FLAT shoes (p=0.027). No other conditions

Discussion

Users who walked with rocker shoes with a radius of 40% of leg length (R40) had reduced oxygen consumption rates compared with using flat rocker shoes, regardless of lift (REG and FLAT). Users also had reductions in oxygen consumption rate when using either of the other rocker shoes (R25 or R55) compared with the FLAT shoes, but not compared with the REG shoes. The R40 shoes were not found to significantly reduce oxygen consumption compared with the R25 or R55 shoes. A trend is seen in the data

Conflict of interest statement

The authors have no conflicts of interest to declare.

Acknowledgements

The authors would like to acknowledge the use of the VA Chicago Motion Analysis Research Laboratory. We would like to thank Rebecca Stine for her help with data collection and analysis, Stefania Fatone for her critical review of the manuscript, Kathy Waldera for her help with making the rocker shoes, and Sara Koehler and Brian Ruhe for their help with statistics used in this study. This publication was made possible by Grant number R03-HD050428-01A2 from the NIH. Its contents are solely the

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Rocker-profile design shoes improve pendular energy recovery in walking with no effects on total mechanical work
2022, Journal of Biomechanics
Rocker-profile design shoes are commonly used in clinical settings. Such footwear reduces in-shoe pressure over the forefoot area during the gait, and depending on the rocker-profile type (i.e., toe-only, heel negative, or double rocker), affects lower limb kinematics, kinetics, and muscle electromyographic activity. However, whether wearing rocker-profile shoes influence the dynamics of the body centre of mass (BCoM) is unknown. We used a mathematical procedure combining Lissajous contours and Fourier analysis to describe the 3D trajectory of the BCoM in walking with rocker-profile (RollingSole) and flat (Control) shoes at 0.97, 1.25, and 1.53 m s⁻¹ in 30 participants. Harmonics amplitude and phase were compared using linear and circular statistics, respectively. External ( $W_{ext}$ ), kinematic internal ( $W_{int, k}$ ) and total ( $W_{tot}$ ) mechanical works, and the mechanical energy fraction recovered from a pendular exchange of potential and kinetic energy were also calculated. RollingSole shoes yielded greater $W_{ext}$ (1–9 %; P < 0.05) and fractional pendular energy exchange (1–8 %; P < 0.01), with lower $W_{int, k}$ (2–5 %; P < 0.05) and unchanged $W_{tot}$ (P ≥ 0.30). RollingSole shoes led also to a greater mean height of the BCoM (1–3 %; P < 0.01), and amplitude of the anteroposterior and vertical symmetric, and mediolateral 2nd-to-5th harmonics (1–30 %; P < 0.01). No differences between shoes were found for the harmonics phase (P ≥ 0.14). Our results indicate that RollingSole shoes enhanced an inverted pendulum-like behaviour of the BCoM during walking with no alterations in total mechanical work. This may result from the combination of rocker-profile design and greater BCoM height (through thicker soles) with such shoes, increasing recovery of mechanical energy in step-to-step transitions and mid-stance.
Effect of different forefoot rocker radii on lower-limb joint biomechanics in healthy individuals
2021, Gait and Posture
Previous studies showed that rocker shoes with a stiff forefoot rocker profile significantly reduce peak plantar flexion moment at the ankle (PFM) and peak ankle dorsiflexion (DF). Both parameters are related to Achilles tendon and Plantar Fascia unloading. The shape of an outsole with a forefoot rocker is described with multiple rocker design parameters. The aim of this research is, to determine the relation between different forefoot rocker radii on peak DF and peak PFM at a self-selected walking speed.
10 participants walked in standard shoes and three experimental pairs of shoes with different forefoot rocker radii. Lower extremity kinematics and kinetics were collected while walking on an instrumented treadmill at preferred walking speed and analysed with Statistical Parametric Mapping (SPM) (α = .05; post-hoc α = .05/6).
Peak value analyses showed significant decreases in peak DF, peak PFM, and peak ankle power generation for the rocker conditions. No relevant significant differences were found in spatio-temporal parameters and total work at the ankle joint. SPM showed a significant decrease (% gait cycle) in DF (40–69 %), PFM (7–15 %; 41–68 %; 69–81 %), ankle power (10–15 %; 32–51 %; 55–64 %; 64–67 %; 72–80 %) and foot-to-horizontal angle (FHA) (0–4 %; 40–62 %; 92–100 %) and an increased shank-to-vertical angle (SVA) (44–84 %) for the rocker conditions.
The results of this study suggest that rocker shoes with a proximally placed apex significantly reduce DF and PFM during the third rocker compared with control shoes. This effect is mainly explained by a change in the FHA. Smaller radii cause the largest reductions in DF and PFM, so therefore, a uniform standardisation of the forefoot rocker radius is essential.
Effect of high heel gait on hip and knee-ankle-foot rollover characteristics while walking over inclined surfaces — A pilot study
2019, Foot
Citation Excerpt :
The effective translation of the foot about the hip, knee and ankle joints generates a curved shape, i.e. the rollover shape, corresponding to the stance phase of the gait cycle. These rollover shapes have been determined and analysed for the knee-ankle-foot (KAF) and hip-ankle foot systems, in multiple studies by Curtze et al. and Hansen et al., to investigate the effects of healthy limbs, prosthetics, shoes (including high-heels) on level ground walking [7–15]. In a related study it has been concluded by Hansen and Childress that the rollover shapes for healthy participants do not change significantly upon changing the shoe heel heights as the ankle-foot systems adapt to the varying conditions [16].
Given the massive number of individuals wearing high-heeled shoes, understanding the gait biomechanics associated with their use could provide insight into clinically preventable abnormalities. The effects of inclined surfaces on the high-heeled gait have been investigated in the present pilot study, as most walking surfaces encountered in routine life are rarely perfectly level grounded. The rollover shapes of the high-heel shod gait are calculated to obtain the desired results. An adjustable inclined walkway setup was fabricated and comprising fixed slots permitting discrete and variable angle of inclinations (≤30°). The gait trials were recorded for the heel shod walking of ten healthy female volunteers using the three-dimensional motion analysis system by varying the inclination of the fabricated walkway. From the calculated rollover shapes, the necessary radii of the hip and the knee-ankle- foot rollover shapes were obtained and a repeated measures analysis of variance was carried out to establish the existence of correlation between the angle of inclination and rollover radii. The results of the present pilot study show that for high heel-shod walking there exist variable radii of curvature for early and late stance phases and that the same may vary depending upon the inclination. The same information can be used to modify the design of high-heel shoes to improve the stability while retaining their aesthetics.
Rocker shoe, minimalist shoe, and standard running shoe: A comparison of running economy
2014, Journal of Science and Medicine in Sport
Citation Excerpt :
In one study no changes in metabolic cost between rocker bottom shoes and standard shoes were observed.6 One study reported an increase in energy expenditure during walking with rocker shoes compared with standard shoes,7 and the opposite was found in another study.8 The minimalist shoe is a rather new type of footwear, gaining popularity among runners.
Running with rocker shoes is believed to prevent lower limb injuries. However, it is not clear how running in these shoes affects the energy expenditure. The purpose of this study was, therefore, to assess the effects of rocker shoes on running economy in comparison with standard and minimalist running shoes.
Cross-over design.
Eighteen endurance female runners (age = 23.6 ± 3 years), who were inexperienced in running with rocker shoes and with minimalist/barefoot running, participated in this study. Oxygen consumption, carbon dioxide production, heart rate and rate of perceived exertion were measured while participants completed a 6-min sub-maximal treadmill running test for each footwear condition. The data of the last 2 min of each shoe condition were averaged for analysis. A linear mixed model was used to compare differences among three footwear conditions.
Oxygen consumption during running with rocker shoes was on average 4.5% higher than with the standard shoes (p < 0.001) and 5.6% higher than with the minimalist shoe (p < 0.001). No significant differences were found in heart rate and rate of perceived exertion across three shoe conditions.
Female runners, who are not experienced in running with the rocker shoes and minimalist shoes, show more energy expenditure during running with the rocker shoes compared with the standard and minimalist shoes. As the studied shoes were of different masses, part of the effect of increased energy expenditure with the rocker shoe is likely to be due to its larger mass as compared with standard running shoes and minimalist shoes.
Rollover footwear affects lower limb biomechanics during walking
2014, Gait and Posture
Citation Excerpt :
Effects at the level of the whole body (energy, walking speed) were also negligible. Others have reported some differences in these data with MBT [4,7,9,10]. However, we believe that 6 min of uninterrupted walking at a self selected speed is a superior protocol compared to treadmill walking at a fixed speed since it reflects real world use of footwear, and is thus a better approach to measurement of energy expenditure [9,10].
To investigate the effect of rollover footwear on walking speed, metabolic cost of gait, lower limb kinematics, kinetics, EMG muscle activity and plantar pressure.
Twenty subjects (mean age-33.1 years, height-1.71 m, body mass-68.9 kg, BMI 23.6, 12 male) walked in: a flat control footwear; a flat control footwear weighted to match the mass of a rollover shoe; a rollover shoe; MBT footwear. Data relating to metabolic energy and temporal aspects of gait were collected during 6 min of continuous walking, all other data in a gait laboratory.
The rollover footwear moved the contact point under the shoe anteriorly during early stance, increasing midfoot pressures. This changed internal ankle dorsiflexion moments to plantarflexion moments earlier, reducing ankle plantarflexion and tibialis anterior activity after initial contact, and increasing calf EMG activity. In mid stance the rollover footwear resulted in a more dorsiflexed ankle position but less ankle movement. During propulsion, the rollover footwear reduced peak ankle dorsiflexion, peak internal plantarflexor ankle moments and the range of ankle plantarflexion. Vertical ground reaction loading rates were increased by the rollover footwear. There were no effects on temporal or energy cost of gait and no effect of elevated shoe weight.
Investigating all proposed effects of this footwear concurrently has enabled a more valid investigation of how the footwear effects are interrelated. There were concurrent changes in several aspects of lower limb function, with greatest effects at the foot and ankle, but no change in the metabolic cost of walking.
Modelling the effect of 'heel to toe' roll-over contact on the walking dynamics of passive biped robots
2013, Applied Mathematical Modelling
The ‘heel to toe’ rolling contact has a great influence on the dynamics of biped robots. Here this contact is modelled using the roll-over shape defined in the local co-ordinate system aligned with the stance leg. The roll-over shape is characterised by six constants: forefoot, midfoot and hindfoot gains and length values. A piecewise parabolic polynomial constructed from these six values is able to match the realistic roll-over shape with continuous slope and variable curvature. The effect of these constants and the roll-over shape arc length has been studied on various gait descriptors such as average velocity, step period, inter-leg angle (and hence step length), mechanical energy. The bifurcation diagrams have been plotted for point feet and different gain values. The insight gained by studying the bifurcation diagrams for different gain and length values is not only useful in understanding the stability of the biped walking process but also in the design of prosthetic feet. The discovery of ‘critical values’ for the length and mass ratios for the inter-leg angle δ (and hence step length) bifurcation diagrams, or a ‘critical value’ for forefoot gain in the step period bifurcation diagram, is of particular interest as it would mean a constant step length or step period for a range of acceptable values of forefoot and hindfoot gains. The dependence of the horizontal roll-over shape length and hindfoot/forefoot gains on the actual stance leg angular velocity ${\dot{θ}}_{s}$ and angular displacement (θ_s) values along with the corresponding existence of critical values has also been demonstrated.

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Published by Elsevier Ltd.

Effect of rocker shoe radius on oxygen consumption rate in young able-bodied persons

Abstract

Introduction

Section snippets

Methods

Results

Discussion

Conflict of interest statement

Acknowledgements

Gait Posture

Archives of Physical Medicine and Rehabilitation

Clinical Biomechanics

Gait Posture

Foot (Edinb)

Journal of Biomechanics

Gait Posture

Clinical Biomechanics

Gait Posture

Journal of Biomechanics

Gait Posture

Medical Engineering and Physics

The advantages of a rolling foot in human walking

Journal of Experimental Biology

Normal range of motion of joints in male subjects

Journal of Bone and Joint Surgery