The Importance of Knee Extension at Terminal Stance

The gait cycle is a complex sequence of movements that allows for efficient locomotion. Among the various planes of movement, the sagittal plane plays a pivotal role, particularly during critical phases of walking, such as terminal stance. Understanding the dynamics of knee extension within the sagittal plane during this phase is essential for professionals in the orthotic and prosthetics industry, as it directly impacts the design and functionality of devices aimed at enhancing mobility.

The Sagittal Plane: An Overview The sagittal plane divides the body into left and right halves, facilitating movements that occur forward and backward. In the context of the gait cycle, movements within this plane include flexion and extension of the knee, hip, and ankle joints. The terminal stance phase, typically occurring when the heel of the leading leg lifts off the ground, is characterized by knee extension, which is crucial for proper weight transfer and balance. 

Consequences of Impaired Knee Extension

Consequences 

Abnormal gait mechanics can significantly impact an individual's musculoskeletal health, leading to a cascade of negative consequences such as muscle weakness, the development of contractures, deformity, and pain. When gait is altered—due to factors like improper alignment, limited range of motion, or compensatory movements—certain muscle groups may become overworked while others weaken due to disuse. This imbalance can result in muscle atrophy and weakness, particularly in the stabilizing muscles that support joint function. Additionally, abnormal gait patterns often place undue stress on specific joints and tissues, contributing to the formation of contractures—shortened muscles or tendons that restrict movement—and deformities that may affect overall posture and biomechanics. Over time, these mechanical inefficiencies can lead to chronic pain as the body struggles to compensate for the altered movement patterns, creating a vicious cycle that further exacerbates mobility issues and diminishes quality of life.

Conclusion  

The significance of the sagittal plane and knee extension during terminal stance in the gait cycle cannot be overstated in the orthotic and prosthetics industry. By understanding the mechanics involved and the consequences of impaired knee extension, professionals can develop better devices, enhance rehabilitation practices, and ultimately improve the mobility and quality of life for their patients. As research continues to evolve, the integration of biomechanical principles into orthotic and prosthetic design will play a critical role in advancing patient care and outcomes.

Introducing X-Tension Bands! 

The primary goal of X-Tension Bands is to encourage knee extension at terminal stance and initial contact. The band serves as a tool to normalize knee mechanics. By providing dorsiflexion resistance, patients gain confidence in allowing the tibia to anteriorly progress over the foot. This resistance enhances stability during single-leg stance and improves step length.

The weight and size of the bands should be proportional to the patient’s needs and any compensatory patterns at the knee. One important consideration that many orthotists, physical therapists, and doctors often overlook when evaluating patients is the underlying cause of knee hyperextension.

There are three primary causes of knee compensations: 

All of these conditions can be effectively addressed using X-Tension Bands. By providing resistance to dorsiflexion, these bands instill confidence in patients as they shift weight over their feet—an approach that may not be intuitive for many clinicians.

The fundamental challenge lies not in product selection, but in the absence of a universal definition of normal gait. If clinicians had a shared understanding of normal gait mechanics, they would be better equipped to select devices that provide the appropriate motion control. 

X-Tension Bands function as a tuning product for the knee. Given the numerous variables involved, it is difficult to pinpoint a specific band thickness for each case. In fact, both excessive knee flexion and extension can be managed in a similar way using the same tool. X-Tension Bands are a post-fitting tool for fine-tuning. Here are a few guidelines to keep in mind: the band thickness should never be less than the thickness of the outer boot. A more effective way to think about this is as follows:

The value proposition of these bands lies in their ability to promote normal gait and enhance quality of life.  Please contact Scott Hinshon, CO at scott@launchpad-op.com for questions or additional information. 

Launchpad is excited to introduce a new family of thermoplastic components for articulated AFOs!

Realize the benefits of double action ankle joints without the large hardware and difficult fabrication. Featured below is the fully outfitted articulated AFO that combines pivot ankle joints, snapstop and X-tension components. This trio combination allows you to tune the shank-to-floor alignments with resist or stop motion to optimize gait and outcomes for your patient.

Available in pediatric and adult sizes, the pivot ankle joint coordinates sizing with the snapstop product. The pivot joint on your AFO is simply a mechanism of movement that gives you an opportunity to control motion in the sagittal plane. By itself it brings no value to the end user until you resist or stop motion. The index bushing prevents rotation during assembly. Like snapstop, gross lateral projection is reduced by molding around the smallest common denominator and then installing the thread height after fabrication.