The Effect of Excessive Subtalar Inversion/Eversion on the Dynamic Function of the Soleus and Gastrocnemius During the Stance Phase

2009 ◽  
Author(s):  
Ruoli Wang ◽  
Elena M. Gutierrez-Farewik
Keyword(s):  
Subtalar Joint ◽  
Stance Phase ◽  
Heel Strike ◽  
Neutral Position ◽  
Plantar Flexor ◽  
Normal Gait ◽  
Joint Axis ◽  
Dynamic Function ◽  
Foot Pronation ◽  
Pathological Gait

Gastrocnemius and soleus are often considered as ankle plantarflexors. Their dynamic functions in normal and pathological gait have been well-studied. However, in a neutral position, the tendon passes medial to the subtalar joint axis and therefore produces an inversion moment in addition to the plantar-flexor moment [1]. It was believed that gastrocnemius and soleus are the major dynamic stabilizers preventing excess foot pronation. During normal gait, the subtalar joint experiences rapid eversion following heel strike and subsequent inversion during terminal stance [2]. Varus and valgus foot positions caused by excessive subtalar inversion/eversion can be found in spastic and flaccid paralysis [3]. Although it is widely understood that muscle forces can have important local and remote effects on joints and segments [4], the interrelations between dynamic gastrocnemius and soleus functions and excessive subtalar inversion/eversion remain unclear.

Relationship Between Neutral Subtalar Joint Position and Pattern of Rearfoot Motion During Walking

1994 ◽  
Vol 15 (3) ◽  
pp. 141-145 ◽  
Author(s):  
Thomas McPoil ◽  
Mark W. Cornwall
Keyword(s):  
Subtalar Joint ◽  
Stance Phase ◽  
Heel Strike ◽  
Neutral Position ◽  
Typical Pattern ◽  
Healthy Young Adult ◽  
Phase Duration ◽  
Foot Posture ◽  
Rearfoot Motion ◽  
The Relationship

The purpose of this study was to determine the relationship between the angle formed by the rearfoot when the subtalar joint is positioned in neutral and the pattern of rearfoot motion during walking. Each lower extremity for 50 healthy young adult subjects (mean age 25.5 years) was videotaped and the pattern of rearfoot motion was assessed using two-dimensional analysis. The results indicate that the rearfoot is slightly inverted before heel strike and that the average time to maximum pronation occurs at approximately 37.9% of the stance phase duration. Contrary to a previously published theory, the “neutral” position of the rearfoot for the typical pattern of rearfoot motion during the walking cycle was found to be resting standing foot posture rather than subtalar joint neutral position.

In Vivo Forces in the Plantar Fascia During the Stance Phase of Gait

2003 ◽  
Vol 93 (6) ◽  
pp. 429-442 ◽  
Author(s):  
Erin D. Ward ◽  
Kevin M. Smith ◽  
Jay R. Cocheba ◽  
Patrick E. Patterson ◽  
Robert D. Phillips
Keyword(s):  
Muscle Activity ◽  
Plantar Fasciitis ◽  
Subtalar Joint ◽  
Stance Phase ◽  
Plantar Fascia ◽  
Heel Strike ◽  
Cadaveric Specimen ◽  
Orthopedic Medicine ◽  
Loading System

Plantar fasciotomies have become commonplace in podiatric and orthopedic medicine for the treatment of plantar fasciitis. However, several complications have been associated with plantar fascial release. It has been speculated that the cause of these complications is excessive release of the plantar fascia. The aim of this project was to determine whether the amount of fascia released, from medial to lateral, causes a significant increase in force in the remaining fascia. A dynamic loading system was developed that allowed a cadaveric specimen to replicate the stance phase of gait. The system was capable of applying appropriate muscle forces to the extrinsic tendons on the foot and replicating the in vivo timing of the muscle activity while applying force to the tibia and fibula from heel strike to toe-off. As the plantar fascia was sequentially released from medial to lateral, from intact to 33% released to 66% released, the real-time force and the duration of force in the remaining fascia increased significantly, and the force was shifted later in propulsion. In addition, the subtalar joint was unable to resupinate as the amount of fascia release increased, indicating a direct relationship between the medial band of the plantar fascia and resupination of the subtalar joint during late midstance and propulsion. (J Am Podiatr Med Assoc 93(6): 429-442, 2003)

Frontal Plane Moments Do Not Accurately Reflect Ankle Dynamics during Running

2005 ◽  
Vol 21 (1) ◽  
pp. 85-95 ◽  
Author(s):  
Kristian M. O’Connor ◽  
Joseph Hamill
Keyword(s):  
Ankle Joint ◽  
Subtalar Joint ◽  
Stance Phase ◽  
Three Dimensional ◽  
Frontal Plane ◽  
Joint Moment ◽  
Muscle Action ◽  
Universal Joint ◽  
Joint Moments ◽  
Joint Axis

The ankle joint has typically been treated as a universal joint with moments calculated about orthogonal axes and the frontal plane moment generally used to represent the net muscle action about the subtalar joint. However, this joint acts about an oblique axis. The purpose of this study was to examine the differences between joint moments calculated about the orthogonal frontal plane axis and an estimated subtalar joint axis. Three-dimensional data were colected on 10 participants running at 3.6 m/s. Joint moments, power, and work were calculated about the orthogonal frontal plane axis of the foot and about an oblique axis representing the subtalar joint. Selected parameters were compared with a paired t-test (α = 0.05). The results indicated that the joint moments calculated about the two axes were characteristically different. A moment calculated about an orthogonal frontal plane axis of the foot resulted in a joint moment that was invertor in nature during the first half of stance, but evertor during the second half of stance. The subtalar joint axis moment, however, was invertor during most of the stance. These two patterns may result in qualitatively different interpretations of the muscular contributions at the ankle during the stance phase of running.

scholarly journals Wearable Sensor-Based Real-Time Gait Detection: A Systematic Review

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2727
Author(s):  
Hari Prasanth ◽  
Miroslav Caban ◽  
Urs Keller ◽  
Grégoire Courtine ◽  
Auke Ijspeert ◽  
...  
Keyword(s):  
Systematic Review ◽  
Gait Analysis ◽  
Real Time ◽  
Wearable Sensors ◽  
Pressure Sensors ◽  
Clinical Applications ◽  
Performance Comparison ◽  
Heel Strike ◽  
Rule Based ◽  
Pathological Gait

Gait analysis has traditionally been carried out in a laboratory environment using expensive equipment, but, recently, reliable, affordable, and wearable sensors have enabled integration into clinical applications as well as use during activities of daily living. Real-time gait analysis is key to the development of gait rehabilitation techniques and assistive devices such as neuroprostheses. This article presents a systematic review of wearable sensors and techniques used in real-time gait analysis, and their application to pathological gait. From four major scientific databases, we identified 1262 articles of which 113 were analyzed in full-text. We found that heel strike and toe off are the most sought-after gait events. Inertial measurement units (IMU) are the most widely used wearable sensors and the shank and foot are the preferred placements. Insole pressure sensors are the most common sensors for ground-truth validation for IMU-based gait detection. Rule-based techniques relying on threshold or peak detection are the most widely used gait detection method. The heterogeneity of evaluation criteria prevented quantitative performance comparison of all methods. Although most studies predicted that the proposed methods would work on pathological gait, less than one third were validated on such data. Clinical applications of gait detection algorithms were considered, and we recommend a combination of IMU and rule-based methods as an optimal solution.

scholarly journals The Importance of Being Earnest about Shank and Thigh Kinematics Especially When Using Ankle-Foot Orthoses

2010 ◽  
Vol 34 (3) ◽  
pp. 254-269 ◽  
Author(s):  
Elaine Owen
Keyword(s):  
Joint Kinematics ◽  
Foot Orthoses ◽  
Traditional Beliefs ◽  
Vertical Angle ◽  
Gait Biomechanics ◽  
Normal Gait ◽  
Ankle Foot Orthoses ◽  
Pathological Gait ◽  
Kinematics And Kinetics

This paper reviews and summarizes the evidence for important observations of normal and pathological gait and presents an approach to rehabilitation and orthotic management, which is based on the significance of shank and thigh kinematics for standing and gait. It discusses normal gait biomechanics, challenging some traditional beliefs, the interrelationship between segment kinematics, joint kinematics and kinetics and their relationship to orthotic design, alignment and tuning. It proposes a description of four rather than three rockers in gait; a simple categorization of pathological gait based on shank kinematics abnormality; an algorithm for the designing, aligning and tuning of AFO-Footwear Combinations; and an algorithm for determining the sagittal angle of the ankle in an AFO. It reports the results of research on Shank to Vertical Angle alignment of tuned AFO-Footwear Combinations and on the use of ‘point loading’ rocker soles.

The Subtalar Joint Axis Locator

2006 ◽  
Vol 96 (3) ◽  
pp. 212-219 ◽  
Author(s):  
Simon K. Spooner ◽  
Kevin A. Kirby
Keyword(s):  
Subtalar Joint ◽  
Dynamic Capabilities ◽  
Three Dimensional ◽  
Spatial Location ◽  
Exit Point ◽  
Neck Position ◽  
Dorsal Aspect ◽  
Joint Axis ◽  
Preliminary Study ◽  
Rotational Motions

A new clinical device, the subtalar joint axis locator, was created to track the three-dimensional location of the subtalar joint axis during weightbearing movements of the foot. The assumption was that if the anterior exit point of the subtalar joint axis is stationary relative to the dorsal aspect of the talar neck, then, by performing radiographs of the feet with the subtalar joint axis locator in place on the foot, the ability of the locator to track rotations and translations of the talar neck and thus the subtalar joint axis in space could be approximated. In this preliminary study of two adults, the subtalar joint axis locator accurately tracked the talar neck position during weightbearing rotational motions of the subtalar joint. The device was also used in a series of subjects to determine its dynamic capabilities. It is possible, then, that the subtalar joint axis locator can reliably track the spatial location of the subtalar joint axis during weightbearing movements of the foot. (J Am Podiatr Med Assoc 96(3): 212–219, 2006)

The Effect of Tibiotalar Fixation on Foot Biomechanics

1997 ◽  
Vol 18 (12) ◽  
pp. 792-797 ◽  
Author(s):  
Jennifer S. Wayne ◽  
Keith W. Lawhorn ◽  
Kenneth E. Davis ◽  
Karanvir Prakash ◽  
Robert S. Adelaar
Keyword(s):  
Subtalar Joint ◽  
Sagittal Plane ◽  
Lower Limbs ◽  
Coronal Plane ◽  
Neutral Position ◽  
Talonavicular Joint ◽  
Tibiotalar Joint ◽  
Contact Areas ◽  
Joint Contact ◽  
Peak Pressures

Contact areas and peak pressures in the posterior facet of the subtalar and the talonavicular joints were measured in cadaver lower limbs for both the normal limb and after fixation of the tibiotalar joint. Six joints were fixed in neutral, in 5–7° of varus and of valgus. Ten degrees of equinus angulation was also studied. Each position of fixation was tested independently. Neutral was defined as fixation without coronal or sagittal plane angulation compared with prefixation alignment of the specimen. When compared with normal unfused condition, peak pressures increased, and contact areas decreased in the subtalar joint for specimens fixed in neutral, varus, and valgus. However, the change in peak pressure for neutral fusion compared with normal control was not statistically significant ( P > 0.07). Peak pressures for varus and valgus fixation were significantly different from normal ( P < 0.001). Contact areas for all positions of fixation were significantly different from normal ( P < 0.001). Coronal plane angulation, however, also resulted in significantly lower contact areas compared with neutral fixation ( P < 0.001). Contact areas and peak pressures in the talonavicular joint did not appear to be substantially affected by tibiotalar fixation with coronal plane angulation. Equinus fixation qualitatively increased contact areas and peak pressures in the talonavicular and posterior facet of the subtalar joint. Neutral alignment of the tibiotalar joint in the coronal and sagittal planes altered subtalar and talonavicular joint contact characteristics the least compared with normal controls. Therefore, ankle fusion in the neutral position would be expected to most closely preserve normal joint biomechanics and may limit the progression of degenerative arthrosis of the subtalar joint.

The Influence of Running on Foot Posture and In-Shoe Plantar Pressures

2016 ◽  
Vol 106 (2) ◽  
pp. 109-115 ◽  
Author(s):  
María Bravo-Aguilar ◽  
Gabriel Gijón-Noguerón ◽  
Alejandro Luque-Suarez ◽  
Javier Abian-Vicen
Keyword(s):  
Heel Strike ◽  
Neutral Position ◽  
Training Time ◽  
Plantar Pressures ◽  
Time Integral ◽  
Pressure Time ◽  
Limb Injuries ◽  
Before And After ◽  
Foot Posture ◽  
The Mean

Background: Running can be considered a high-impact practice, and most people practicing continuous running experience lower-limb injuries. The aim of this study was to determine the influence of 45 min of running on foot posture and plantar pressures. Methods: The sample comprised 116 healthy adults (92 men and 24 women) with no foot-related injuries. The mean ± SD age of the participants was 28.31 ± 6.01 years; body mass index, 23.45 ± 1.96; and training time, 11.02 ± 4.22 h/wk. Outcome measures were collected before and after 45 min of running at an average speed of 12 km/h, and included the Foot Posture Index (FPI) and a baropodometric analysis. Results: The results show that foot posture can be modified after 45 min of running. The mean ± SD FPI changed from 6.15 ± 2.61 to 4.86 ± 2.65 (P &lt; .001). Significant decreases in mean plantar pressures in the external, internal, rearfoot, and forefoot edges were found after 45 min of running. Peak plantar pressures in the forefoot decreased after running. The pressure-time integral decreased during the heel strike phase in the internal edge of the foot. In addition, a decrease was found in the pressure-time integral during the heel-off phase in the internal and rearfoot edges. Conclusions: The findings suggest that after 45 min of running, a pronated foot tends to change into a more neutral position, and decreased plantar pressures were found after the run.

Rear Foot Inversion/Eversion During Gait Relative to the Subtalar Joint Neutral Position

1996 ◽  
Vol 17 (7) ◽  
pp. 406-412 ◽  
Author(s):  
Michael Raymond Pierrynowski ◽  
Steve Barry Smith
Keyword(s):  
Subtalar Joint ◽  
Three Dimensional ◽  
Neutral Position ◽  
Foot Care ◽  
Worst Case ◽  
Foot Motion ◽  
Rear Part ◽  
Valid Estimate ◽  
Foot Position ◽  
Foot Orthotic

Clinicians often fabricate foot orthotic devices at the subtalar joint neutral position (STNP) to mimic the position of the rear foot during midstance. However, rear foot motion during gait, relative to the resting standing foot position, not the STNP, is often reported in the literature. The motion of the rear foot relative to a valid estimate of the STNP is unknown. In this study, six experienced foot care specialists manually placed the rear part of the feet of nine subjects at the STNP seven or eight times to obtain a valid estimate of each subject's STNP. The worst-case mean and 95% confidence interval of the STNP estimate for any one subject was 0.0° ± 0.7°. These nine subjects then walked on a motor-driven treadmill, set at 0.89 meters/sec, and three-dimensional estimates of each subject's rear foot inversion/eversion motion were obtained, then averaged over 6 to 26 strides. For most subjects, the rear foot was always everted during stance with mean and standard deviation maximal eversion (7.2° ± 1.2°) occurring at 44% of the total gait cycle. The inversion/eversion orientation during swing was characterized by 1 ° to 2° of eversion, with a small amount of inversion in early swing. These findings have implications for the fabrication of foot orthoses, since the rear foot is rarely near the STNP during stance.

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