Postural Deviations - Biomechanics

Summary

This lecture delves into the intricacies of posture, emphasizing that it's not a static concept but a dynamic interplay of body parts. It clarifies that while there's no 'perfect' posture, some postures can be detrimental, leading to increased muscle activity, joint stress, and various dysfunctions. The lecture introduces the concept of regional interdependence, where one body part's movement affects others, often predictably. It also discusses how poor posture can stem from or lead to injuries and dysfunctions, complicating the identification of the root cause. The talk further explores how the brain adapts to abnormal movement patterns, potentially normalizing them, and outlines three common compensation mechanisms: counterbalancing, hypo/hypermobility, and altered muscle activation. It concludes with an explanation of distortion patterns, which are comprehensive sets of dysfunctions and compensations, and the challenge of discerning between primary and secondary distortions.

Takeaways

• 🧍 Posture is not just about sitting up straight; it's any position of the body and its parts in relation to each other.
• 🏋️‍♂️ Maintaining posture involves dynamic actions and muscle contractions; it's not a static state.
• 🌟 There's no single perfect posture; what's good for one person or task might not be for another.
• ⚠️ Some postures can be abnormal or harmful, leading to increased muscular activity and stress on joints.
• 🔄 Posture can affect and be affected by injuries or dysfunctions, creating a complex relationship.
• 🔗 Regional interdependence means that the movement of one body segment affects adjacent segments in a kinetic chain.
• 🔄 Compensatory movements often follow predictable patterns across individuals due to regional interdependence.
• 👣 Hyperpronation of the ankle can cause a chain reaction affecting posture and movement all the way up to the hips and spine.
• 🧠 The brain adapts to new movement patterns, even if they're abnormal, making them feel normal over time.
• 🔄 Compensations for abnormal movement or injury can occur through counterbalancing, changes in joint mobility, or altered muscle activation.

Q & A

What is the definition of posture as discussed in the lecture?

Posture is defined as the position of the body and the parts of the body in relation to one another. It is not just about sitting up straight and tall, but any position of the body where different parts are positioned relative to one another.

Why is there no single perfect posture according to the lecture?

There is no single perfect posture because what constitutes 'good posture' varies from person to person and is also task-specific. Different activities may require different postures that are optimal for that particular task.

How can poor posture lead to increased muscular activity and joint stress?

Poor posture can cause certain muscles to contract at a higher level than they should, leading to increased stress on joints and tissues. This can result in various dysfunctions, including pain, abnormal movements, or an inability to complete tasks.

What is the concept of regional interdependence as it relates to posture?

Regional interdependence refers to the idea that the movement of one body segment causes movement at adjacent segments within a kinetic chain. This means that the function of one joint is interdependent with the function of neighboring joints.

Why is it difficult to determine whether poor posture causes dysfunction or if dysfunction causes poor posture?

It can be challenging to determine the cause and effect relationship between posture and dysfunction because they can influence each other. Dysfunctions can lead to poor posture, and poor posture can lead to further dysfunctions, creating a complex cycle that is not always easy to unravel.

Can you explain the example given in the lecture about hyperpronation of the ankle and its effects on the body?

When there is hyperpronation of the ankle, it includes dorsiflexion of the talocrural joint and movement of the subtalar and forefoot of the foot. This can cause the tibia to rotate internally, the tibiofemoral joint to flex, and the acetabular femoral joint to internally rotate and flex, leading to abnormal postures or movements up the entire kinetic chain.

What is meant by the brain learning new movement patterns due to abnormal posture?

When a person maintains an abnormal posture for a period, the brain adapts and starts to perceive this new pattern as the normal way to move. This can lead to the brain no longer recognizing the abnormality, and thus not signaling the need for correction.

What are the three common ways that compensations occur in the body due to abnormal movement or injury?

The three common ways compensations occur are: 1) Counterbalance, where the body shifts part of itself in the opposite direction to balance out another part, 2) Hypomobility leading to hypermobility in adjacent joints to compensate for the lack of mobility, and 3) Changes in muscle activation, where some muscles become chronically shortened or hypertonic, while others become hypotonic or chronically lengthened.

What is a distortion pattern in the context of posture and body mechanics?

A distortion pattern is a pattern of dysfunctions or compensations that emerge from a combination of primary and secondary distortions. Primary distortions are initial problems in a specific area of the body, while secondary distortions are problems or compensations that occur in response to the primary distortion.

Why is it important to address both primary and secondary distortions when dealing with posture issues?

Addressing both primary and secondary distortions is important because they can be interconnected. Even if it's not clear which came first, addressing them together can help resolve the overall pattern of distortions and improve posture and function.