Category: Biomechanics

Merton Root

Posted on March 15, 2023 by - Biomechanics, M

Merton Root (1915-1995) was an American podiatrist who made significant contributions to the field of podiatry, particularly in the area of biomechanics. He developed a systematic approach to the examination, diagnosis, and treatment of foot and ankle disorders that came to be known as the “Root method.”

The Root method emphasizes the importance of understanding the relationship between the foot’s structure and its function, and how abnormalities in one can affect the other. Root believed that proper diagnosis and treatment of foot disorders required a comprehensive understanding of these relationships.

Root was also a co-founder of the American Academy of Podiatric Sports Medicine and was instrumental in establishing podiatry as a recognized medical specialty in the United States. His contributions to the field of podiatry continue to be recognized and studied by podiatrists today.

Simmonds test

Posted on March 10, 2023 by - Biomechanics, S

The Simmonds test, also known as the Thompson test, is a clinical assessment tool used by podiatrists and other healthcare professionals to evaluate the integrity of the Achilles tendon in the foot and ankle. The test is named after the British surgeon, Sir William John Simmonds, who first described the technique in the early 20th century.

During the Simmonds test, the patient is asked to lie prone (face down) with the feet hanging off the edge of a table or examination bed. The examiner then squeezes the calf muscle with one hand while observing the movement of the foot with the other hand.

If the Achilles tendon is intact, the foot should plantar flex or point downwards when the calf muscle is squeezed. However, if the Achilles tendon is ruptured, there will be no movement of the foot, indicating a complete tear of the tendon.

The Simmonds test can be useful in diagnosing Achilles tendon ruptures, which can occur as a result of overuse injuries or trauma to the foot and ankle. Treatment options for Achilles tendon ruptures may include immobilization with a cast or brace, physical therapy, and in some cases, surgery to repair the torn tendon.

Overall, the Simmonds test is a simple, non-invasive clinical tool that can provide valuable information about the integrity of the Achilles tendon in the foot and ankle, and help guide treatment decisions for a range of foot and ankle conditions.

Silfverskiold test

Posted on March 10, 2023 by - Biomechanics, S

the Silfverskiold test is a clinical examination technique used by healthcare professionals, particularly podiatrists and orthopedic surgeons, to assess the extent of gastrocnemius muscle contracture in the lower leg. The test is named after the Swedish surgeon, Dr. Harald Silfverskiold, who developed the technique in the 1920s.

During the Silfverskiold test, the patient is asked to lie prone (face down) with both legs hanging off the edge of a table or examination bed. The examiner then dorsiflexes the ankle passively while stabilizing the knee joint in full extension and in 20 degrees of knee flexion. The amount of ankle dorsiflexion available is then measured and compared between the two positions.

If there is a significant difference in ankle dorsiflexion between the two positions, with more dorsiflexion available in the flexed knee position, it suggests that there is gastrocnemius muscle contracture present. This is because the gastrocnemius muscle crosses both the ankle and knee joints, and in the extended knee position, it is in a shortened position, which limits ankle dorsiflexion.

The Silfverskiold test can be useful in diagnosing and monitoring gastrocnemius muscle contracture, which can contribute to a range of foot and ankle conditions, including plantar fasciitis, Achilles tendonitis, and flatfoot deformity. Treatment options may include stretching exercises, physical therapy, and orthotics to improve ankle range of motion and prevent further complications.

Overall, the Silfverskiold test is a simple, non-invasive clinical tool that can provide valuable information about the extent of gastrocnemius muscle contracture in the lower leg, and help guide treatment decisions for a range of foot and ankle conditions.

Coleman block test

Posted on March 10, 2023 by - Biomechanics, C

The Coleman block test, also known as the subtalar joint neutral test, is a clinical assessment tool used by podiatrists and other healthcare professionals to evaluate the alignment and motion of the subtalar joint in the foot. The test is named after Dr. James Coleman, who developed the technique in the early 1980s.

During the Coleman block test, the patient stands with the foot to be tested on a specially designed block, with the forefoot and toes elevated and the heel hanging off the edge of the block. The examiner then uses their hands to gently invert and evert the hindfoot, while applying axial compression to the leg.

The goal of the Coleman block test is to find the position of subtalar joint neutral, which is the position in which the subtalar joint is in a neutral or mid-range position, with neither excessive pronation nor supination. This position is considered to be the optimal alignment for the subtalar joint during weight-bearing activities.

The Coleman block test can be useful in diagnosing and treating various foot and ankle conditions, including flatfoot deformity, plantar fasciitis, and ankle sprains. Treatment options for abnormal subtalar joint alignment may include orthotics, physical therapy, and footwear modifications to restore balance and improve foot function.

Overall, the Coleman block test is a simple, non-invasive clinical tool that can provide valuable information about subtalar joint alignment and function in the foot, and help guide treatment decisions for a range of foot and ankle conditions.

Tissue stress theory

Posted on March 10, 2023 by - Biomechanics, T

The tissue stress theory of podiatric biomechanics is a framework used to understand the effects of mechanical stress on the soft tissues of the foot and lower extremities. This theory was first introduced by Dr. J. Amos and Dr. D. Roukis in the early 2000s and is based on the principles of Wolff’s law, which states that bone and soft tissue will adapt to the loads under which they are placed.

According to the tissue stress theory, abnormal mechanical stress on the soft tissues of the foot and lower extremities can lead to overuse injuries such as plantar fasciitis, Achilles tendonitis, and stress fractures. The theory emphasizes the importance of identifying and addressing the underlying mechanical factors that contribute to tissue stress, including abnormal foot and ankle mechanics, poor footwear choices, and training errors.

Podiatrists use various assessment tools, including gait analysis and biomechanical examination, to identify abnormal mechanical stress on the soft tissues of the foot and lower extremities. Treatment options may include orthotics, physical therapy, and footwear modifications to reduce stress and improve tissue adaptation.

The tissue stress theory also highlights the importance of patient education and self-management strategies, such as appropriate warm-up and cool-down exercises, proper stretching techniques, and gradual increases in activity level to prevent overuse injuries.

Overall, the tissue stress theory of podiatric biomechanics provides a useful framework for understanding the effects of mechanical stress on the soft tissues of the foot and lower extremities, and can inform treatment and prevention strategies for overuse injuries in these areas.

Sagittal plane theory

Posted on March 10, 2023 by - Biomechanics, S

In the context of podiatric biomechanics, sagittal plane theory is used to understand and diagnose problems with movement in the front-to-back plane of the foot and ankle. This plane divides the foot and ankle into anterior (front) and posterior (back) halves and includes movements such as dorsiflexion (lifting the foot towards the shin) and plantarflexion (pointing the foot downwards).

The sagittal plane theory is particularly important in the assessment and treatment of conditions such as flat feet (pes planus) and high arches (pes cavus), which can result in abnormal foot mechanics in the sagittal plane. For example, flat feet can be associated with excessive pronation (inward rolling) of the foot, which can lead to problems such as heel pain, arch pain, and shin splints. High arches, on the other hand, can be associated with limited ankle dorsiflexion, which can lead to compensatory movements and increased stress on the forefoot.

Podiatrists use various assessment tools, including gait analysis and biomechanical examination, to identify abnormalities in foot and ankle mechanics in the sagittal plane. Treatment options may include orthotics, physical therapy, or surgery, depending on the severity and underlying cause of the problem.

Overall, the sagittal plane theory is an important framework for understanding and addressing movement problems in the front-to-back plane of the foot and ankle, and plays a crucial role in the diagnosis and treatment of many podiatric conditions.

Root theory

Posted on March 10, 2023 by - Biomechanics, R

The root theory of podiatric biomechanics is a framework that helps podiatrists understand and diagnose problems with foot and ankle mechanics. The theory was first introduced by Dr. Merton Root in the 1960s and is still widely used today.

According to the root theory, the foot can be divided into three sections: the rearfoot, midfoot, and forefoot. Each section has a specific role in foot function and contributes to overall biomechanics.

The rearfoot is responsible for providing stability and shock absorption. It includes the heel bone (calcaneus) and ankle joint. The midfoot is responsible for providing a flexible arch that can adapt to uneven surfaces. It includes the bones of the arch (navicular, cuboid, and cuneiforms). The forefoot is responsible for propulsion and balance during gait. It includes the metatarsal bones and toes.

The root theory also describes three planes of motion that can affect foot function: sagittal (front-to-back), transverse (side-to-side), and frontal (up-and-down). Problems in any of these planes can lead to biomechanical issues and pain.

Based on the root theory, podiatrists use a variety of assessment tools, including gait analysis and biomechanical examination, to identify abnormalities in foot and ankle mechanics. They may then recommend treatments such as orthotics, physical therapy, or surgery to improve function and reduce pain.