Translational and rotational joint power terms in a six degree-of-freedom model of the normal ankle complex

doi:10.1016/0021-9290(94)90194-5

Journal of Biomechanics

Volume 27, Issue 12, December 1994, Pages 1447-1457

https://doi.org/10.1016/0021-9290(94)90194-5 Get rights and content

Abstract

We hypothesized that defining joint power (JP) merely on the basis of joint rotations ignores important translational power terms, and may not adequately represent the energy flow profile for a given muscle group. A novel six degree-of-freedom (6 DOF) model of the ankle complex was implemented, accounting for previously ignored joint translations as well as traditional rotations. Foot and shank kinematic and kinetic data were collected over a stride cycle on five male and five female adults, walking five trials each at 0.69 statures s⁻¹. During intra-subject analyses, ensemble averages were calculated (n=5) for JP associated with each DOF, and for related velocity and force/moment data. Translational joint velocities typically peaked below 10% of the mean walking velocity. The largest peak in JP occurred for the rotational DOF associated with dorsi/planter flexion (360 W). The next largest peak in JP was for the vertical translational DOF, and was nearly 10% of the predominant peak. Positive work during push-off was significantly less p≤0.05) for the 6 DOF model (27.9 J) than for either 1 or 3 DOF rotational models (30.3 and 29.9 J, respectively). Negative work during early stance was significantly less for the 6 DOF model (−10.3 J) than for either the 1 or 3 DOF models (−13.1 and −12.6 J, respectively). Inter-subject analyses (n=50) were conducted for JP data only, with similar results. We conclude that translational JP terms are of practical importance in mechanical energy studies, and may be of particular concern when evaluating energy storing prostheses, when summing total power at several joints, and when studying pathologies that disturb joint geometry.

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F.L. Buczek et al.

Translational and rotational joint power terms in a six degree-of-freedom model of the ankle complex

F.L. Buczek et al.

Translational and rotational joint power terms in a six degree-of-freedom model of the ankle complex

Cited by (62)

Quantification of push-off and collision work during step-to-step transition in amputees walking at self-selected speed: Effect of amputation level
2024, Journal of Biomechanics
Maintaining forward walking during human locomotion requires mechanical joint work, mainly provided by the ankle–foot in non-amputees. In lower-limb amputees, their metabolic overconsumption is generally attributed to reduced propulsion. However, it remains unclear how altered walking patterns resulting from amputation affect energy exchange. The purpose of this retrospective study was to investigate the impact of self-selected walking speed (SSWS) on mechanical works generated by the ankle–foot and by the entire lower limbs depending on the level of amputation. 155 participants, including 47 non-amputees (NAs), 40 unilateral transtibial amputees (TTs) and 68 unilateral transfemoral amputees (TFs), walked at their SSWS. Positive push-off work done by the trailing limb ( $W_{StS}^{+}$ ) and its associated ankle–foot ( $W_{ankle - f o o t}^{+}$ ), as well as negative collision work done by the leading limb ( $W_{StS}^{-}$ ) were analysed during the transition from prosthetic limb to contralateral limb. An ANCOVA was performed to assess the effect of amputation level on mechanical works, while controlling for SSWS effect. After adjusting for SSWS, NAs produce more push-off work with both their biological ankle–foot and trailing limb than amputees do on prosthetic side. Using the same type of prosthetic feet, TTs and TFs can generate the same amount of prosthetic $W_{ankle - f o o t}^{+}$ , while prosthetic $W_{StS}^{+}$ is significantly higher for TTs and remains constant with SSWS for TFs. Surprisingly and contrary to theoretical expectations, the lack of propulsion at TFs’ prosthetic limb did not affect their contralateral $W_{StS}^{-}$ , for which a difference is significant only between NAs and TTs. Further studies should investigate the relationship between the TFs' inability to increase prosthetic limb push-off work and metabolic expenditure.
Impact of pronated foot on energetic behavior and efficiency during walking
2023, Gait and Posture
The longitudinal arch of the foot acts like a spring during stance and contributes to walking efficiency. Pronated foot characterized by a collapsed medial longitudinal arch may have the impaired spring-like function and poor walking efficiency. However, the differences in the energetic behavior during walking between individuals with pronated foot and neutral foot have not been considered.
How does the energetic behavior within the foot and proximal lower limb joints in pronated foot affect walking efficiency?
Twenty-one healthy young adults were classified into neutral foot and pronated foot based on the Foot Posture Index score. All subjects walked across the floor and attempted to have the rearfoot and forefoot segments contact separate force plates to analyze the forces acting on isolated regions within the foot. Kinematic and kinetic data were recorded by a three-dimensional motion capture system. The hip, knee, ankle, and mid-tarsal joint power was quantified using a 6-degree-of-freedom joint power method. To qualify total power within all structures of the foot and forefoot, we used a unified deformable segment analysis. Additionally, we calculated the center of mass power to quantify the total power of the whole body
There is no difference in the mid-tarsal joint work between the pronated foot and neutral foot. On the other hand, pronated foot exhibited greater net negative work at structures distal to the forefoot during walking. Additionally, pronated foot exhibited less net positive work at the ankle and center of mass during walking compared to neutral foot.
Individuals with pronated foot generate the mid-tarsal joint work by increasing the work absorbed at structures distal to the forefoot, which results in reduced energy efficiency during walking. That energy inefficiency may reduce positive work at the ankle and affect the walking efficiency in individuals with pronated foot.
Characterizing the mechanical function of the foot's arch across steady-state gait modes
2023, Journal of Biomechanics
The arch of the human foot has historically been likened to either a truss, a rigid lever, or a spring. Growing evidence indicates that energy is stored, generated, and dissipated actively by structures crossing the arch, suggesting that the arch can further function in a motor- or spring-like manner. In the present study, participants walked, ran with a rearfoot strike pattern, and ran with a non-rearfoot strike pattern overground while foot segment motions and ground reaction forces were recorded. To quantify the midtarsal joint’s (i.e., arch’s) mechanical behavior, a brake-spring-motor index was defined as the ratio between midtarsal joint net work and the total magnitude of joint work. This index was statistically significantly different between each gait condition. Index values decreased from walking to rearfoot strike running to non-rearfoot strike running, indicating that the midtarsal joint was most motor-like when walking and most spring-like in non-rearfoot running. The mean magnitude of elastic strain energy stored in the plantar aponeurosis mirrored the increase in spring-like arch function from walking to non-rearfoot strike running. However, the behavior of the plantar aponeurosis could not account for a more motor-like arch in walking and rearfoot strike running, given the lack of main effect of gait condition on the ratio between net work and total work performed by force in the plantar aponeurosis about the midtarsal joint. Instead, the muscles of the foot are likely altering the motor-like mechanical function of the foot’s arch, the operation of these muscles between gait conditions warrants further investigation.
Can changes in midsole bending stiffness of shoes affect the onset of joint work redistribution during a prolonged run?
2022, Journal of Sport and Health Science
Citation Excerpt :
Our study only reported sagittal plane joint work because the main focus of this investigation was to estimate the contribution of the joint flexor/extensor muscle groups. Also, the sagittal plane work has been shown to be the major determinant of total joint work during human gait.43 Furthermore, we did not control for the striking pattern of the runners.
This study aimed to investigate if changing the midsole bending stiffness of athletic footwear can affect the onset of lower limb joint work redistribution during a prolonged run.
Fifteen trained male runners (10-km time of <44 min) performed 10-km runs at 90% of their individual speed at lactate threshold (i.e., when change in lactate exceeded 1 mmol/L during an incremental running test) in a control and stiff shoe condition on 2 occasions. Lower limb joint kinematics and kinetics were measured using a motion capture system and a force-instrumented treadmill. Data were acquired every 500 m.
Prolonged running resulted in a redistribution of positive joint work from distal to proximal joints in both shoe conditions. Compared to the beginning of the run, less positive work was performed at the ankle (approximately 9%; p ≤ 0.001) and more positive work was performed at the knee joint (approximately 17%; p ≤ 0.001) at the end of the run. When running in the stiff shoe condition, the onset of joint work redistribution at the ankle and knee joints occurred at a later point during the run.
A delayed onset of joint work redistribution in the stiff condition may result in less activated muscle volume, because ankle plantar flexor muscles have shorter muscles fascicles and smaller cross-sectional areas compared to knee extensor muscles. Less active muscle volume could be related to previously reported decreases in metabolic cost when running in stiff footwear. These results contribute to the notion that footwear with increased stiffness likely results in reductions in metabolic cost by delaying joint work redistribution from distal to proximal joints.
Deformable foot orthoses redistribute power from the ankle to the distal foot during walking
2021, Journal of Biomechanics
Recently, carbon fiber plates, or orthoses, have been incorporated into footwear to improve running performance, presumably through improved energy storage and return. However, few studies have explored the energetic effects these orthoses have on the distal foot, have utilized such orthoses in walking, and none have sought to specifically harness metatarsophalangeal joint deformation to store and return energy to the ankle–foot complex. To address these gaps, we developed and tested a deformable carbon fiber foot orthosis aiming to harness foot energetics and quantify the resulting effects on ankle energetics during walking in healthy adults. Eight subjects walked under three conditions: barefoot (BF), with minimalist shoes (SH), and with bilateral, deformable foot orthoses in the minimalist shoes (ORTH). Ankle and distal foot energetics, foot-to-floor and ankle angle, stance time, step length, and max center of pressure (COP) position were calculated. When walking with the orthoses, subjects showed 263.6% increase in positive distal foot work along with a 31.9% decrease in ankle work and little to no change in the overall ankle–foot complex work. Step length, stance time, and max anterior COP position significantly increased with orthosis use. No statistical or visual differences were found between BF and SH conditions indicating that our findings were due to the foot orthoses. These results suggest this foot orthosis redistributes power from the ankle to the distal foot for healthy adults, reducing the energetic demand on the ankle. These results lay the foundation for designing orthotics and footwear to improve ankle–foot energetics for clinical populations.
Effects of age and locomotor demand on foot mechanics during walking
2021, Journal of Biomechanics
Older adults exhibit reductions in push-off power that are often attributed to deficits in plantarflexor force-generating capacity. However, growing evidence suggests that the foot may also contribute to push-off power during walking. Thus, age-related changes in foot structure and function may contribute to altered foot mechanics and ultimately reduced push-off power. The purpose of this paper was to quantify age-related differences in foot mechanical work during walking across a range of speeds and at a single fixed speed with varied demands for push-off power. 9 young and 10 older adults walked at 1.0, 1.2, and 1.4 m/s, and at 1.2 m/s with an aiding or impeding horizontal pulling force equal to 5% BW. We calculated foot work in Visual3D using a unified deformable foot model, accounting for contributions of structures distal to the hindfoot’s center-of-mass. Older adults walked while performing less positive foot work and more negative net foot work (p < 0.05). Further, we found that the effect of age on mechanical work performed by the foot and the ankle–foot complex increased with increased locomotor demand (p < 0.05). Our findings suggest that during walking, age-related differences in foot mechanics may contribute to reduced push-off intensity via greater energy loss from distal foot structures, particularly during walking tasks with a greater demand for foot power generation. These findings are the first step in understanding the role of the foot in push-off power deficits in older adults and may serve as a roadmap for developing future low-cost mobility interventions.

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²: This study was performed while Dr. Buczek was a Staff Fellow at the National Institute of Arthritis and Musculoskeletal and Skin Diseases.

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Translational and rotational joint power terms in a six degree-of-freedom model of the normal ankle complex

Abstract

J. Biomechanics

J. Biomechanics

Am. J. Physiol.

Human Mm. Sci.

The influence of total knee-replacement design on walking and stair-climbing

J. Bone Surg.

Gait analysis as a tool to assess joint kinetics

Biomechanical comparison of the energy-storing capabilities of SACH and Carbon Copy II prosthetic feet during the stance phase of gait in a person with below-knee amputation

Phys. Therapy

The forces and moments in the leg during level walking

Trans. ASME

Three-dimensional kinematics and kinetics of the ankle and knee joints during uphill, level and downhill walking

Stance phase knee and ankle kinematics and kinetics during level and downhill running

Med. Sci. Sports Exerc.

Translational and rotational joint power terms in a six degree-of-freedom model of the ankle complex

Translational and rotational joint power terms in a six degree-of-freedom model of the ankle complex