Muscles In The Knee

By Josh Martin, ATC

Muscles in the Knee

Our knees are an intricate assembly of muscles, ligaments, and bones that work together to facilitate movement. This article aims to provide you with a deeper understanding of the muscles in the knee, the knee muscle anatomy, and the importance of these muscles in our daily lives.

The knee is a simple but complex joint in the human body. The knee is comprised of both static and dynamic stabilizers that work together to stabilize the knee. Static stabilizers are non-contractile and consist of structures such as ligaments, capsules, and menisci. On the other hand, dynamic stabilizers are contractile and consist of structures such as muscle and tendons.

The Crucial Role of Knee Muscles and Tendons in Movement

The muscles and tendons in the knee play a pivotal role in facilitating movement and providing stability. Our ability to walk, run, jump, and even stand relies heavily on these muscles in the knee. Additionally, muscle imbalances can significantly affect the functioning of the knee, leading to discomfort and pain. Thus, understanding the role and importance of these knee muscles and tendons is key to maintaining knee health.

 

Unraveling the Anatomy of the Knee

The knee, one of the most robust and complex joints in the human body, is a marvel of biological engineering. It features a multitude of components, each with its unique role and function. By diving into the knee muscle anatomy, we can better understand its function, the different types of muscles in the knee, and how these elements work together.

How do dynamic stabilizers work?

Dynamic stabilizers are muscles that cross a joint line responsible for co-contracting during movement to provide support to the joint. These Dynamic stabilizers work isometrically or isotonically depending on the movement or performance of exercise. An Isometric contraction is a type of muscle contraction that requires little to no movement.  An isotonic contraction is a type of muscle contraction that requires concentric and eccentric movements.  A concentric contraction is a type of muscle contraction which causes the muscle belly to shorten during a movement. An eccentric contraction is a type of contraction which causes the muscle belly to lengthen during a movement.

What are the Dynamic Stabilizers of the Knee?

Dynamic stabilization of the knee occurs anytime the knee is in motion. These muscles provide support by contracting back in fourth to maintain the musculoskeletal system’s proper anatomical alignment. If damage occurs to one or more of the dynamic stabilizers within the knee, it can impede functions such as strength, range of motion, balance, and postural alignment.

Anatomy

Several muscles work in harmony to facilitate movement and provide stability to the knee. Among them, the quadriceps, the above knee muscle, are powerful extensor muscles that play a significant role in straightening the leg. The hamstrings, the back knee muscle located behind the knee, are crucial flexor muscles that allow bending of the knee. Lastly, the calf muscles, the muscles behind the knee, contribute to plantarflexion and knee stabilization, allowing us to stand on our tiptoes and stabilize the knee joint.

The knee has multiple muscles that support knee stabilization, flexion, and extension. The quadriceps have four main muscles they are Vastus Lateralis, Vastus Intermediacies, Vastus Medialis, and Rectus Femoris. These four muscles are located on the “anterior” front side and aid in knee extension. The hamstrings have three main muscles they are Biceps Femoris, Semitendinosus, and Semimembranosus. These muscles are located on the “posterior” backside of the leg and aid in knee flexion.   In addition to the Hamstrings, there are secondary muscles that help assist during knee flexion. They are the; Sartorius, Popliteus, Gracilis, and the Gastrocnemius. These muscles are located on the posterior aspect of the leg as well.

 Muscular Injury Types

In general, two types of muscular injuries occur around the knee.  The most common muscular injury would be a muscular contusion.  A contusion is caused by a direct blow/ impact to a muscle resulting in damage to soft tissue structures. This injury typically results in swelling and bruising around the affected area. The next most common muscular injury would be a muscular strain. A strain is a partial or complete tear within a muscle. These are commonly observed when the muscular structures are stretched/ pushed beyond their normal limits.  Muscular strains are graded on a scale from one to three based on the severity of the strain.

A grade one strain occurs when five percent or less of the muscular fibers/ structures receive damage during the injury. This usually results in mild pain and bruising with minimal loss of strength and function. A grade two strain occurs when there is more extensive damage to the muscle fibers. This typically results in pain, bruising, loss of strength, and loss of range of motion. Lastly, a grade three strain results in the complete rupture of the muscle or tendon.  Patients with a grade three strain will typically complain of pain, swelling, bruising, and complete function loss.

Exploring Muscle-Related Knee Pain and Its Solutions

Knee pain can often be traced back to muscle problems, such as a pulled muscle in the knee. Identifying the cause of knee pain is the first step toward finding a suitable treatment. This section will delve into the common causes of a pulled muscle in the knee and explore various treatment options to help you find relief and reclaim your mobility.

Muscular injury Treatment

 Muscle contusions and strains around the knee require separate treatment methods depending on the severity of the injury. Typically, contusions and grade one strains require the same treatment method. The “RICE” method will help the injury. RICE stands for rest, ice, compression, and elevation. Anti-inflammatory medication may help prevent/reduce swelling and pain over the affected area. Muscular strains that are greater than a grade one will require a more in-depth recovery process.

Grade two muscular strains typically have a longer recovery time frame and can sometimes be aided with a “PRP” platelet-rich-plasma injection to speed up the recovery process. Following the initial treatment method, physical therapy should help regain the affected area’s strength and function. Grade three muscular strains/complete ruptures often require surgical intervention due to the severity of the injury. Further, doctors will evaluate each case to determine if the surgical intervention will be necessary. Whether or not the surgical intervention will be necessary, a brace will be worn for a short period of time to allow the muscle to recover enough before starting physical therapy.

Where do I get Help?

Strengthening and stretching exercises are crucial to maintaining knee health. Regular exercise can help prevent muscle imbalances, improve stability, and enhance mobility. JOI can help guide you through effective exercises to strengthen your muscles around the knee and proper techniques for stretching to ensure balanced muscle strength and flexibility. We will also provide insight into the behind the knee anatomy to help you understand the importance of these exercises.

No matter what the cause of your injury may be, remember JOI is always here to help. Jacksonville Orthopeadic Institute offers up-to-date clinical practices to help aid in your recovery.

Related Articles: Anatomy of the knee, VMO strengthening exercises, & Cardio Exercises for Bad Knees

JOI and JOI Rehab

JOI Physicians are Northeast Florida’s most respected orthopedic practice.  We continue to offer online new patient appointments. This is another option to make it more convenient to make new patient appointments with less phone hold times. Follow the link below to select your JOI MD and schedule online.

You can still call 904-JOI-2000 to make new patient JOI Physician Appointments if that is your preference.  Our goal is to help you get back to the activities you love without knee pain.

To make appointments with JOI Rehab, please call 904-858-7045.

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Written by: Josh Martin, ATC