From the Guidelines
The quadriceps muscles are dysfunctional in patients with certain conditions, such as COPD, and may benefit from strength training to improve muscle strength and mass.
Condition of the Quadriceps
- The quadriceps muscles play a crucial role in knee function and overall lower limb mobility.
- In patients with COPD, the quadriceps muscles are often weak and dysfunctional, which can lead to decreased mobility and increased risk of falls 1.
- Strength training programs have been shown to improve quadriceps strength and muscle mass in patients with COPD, with benefits including improved muscle function, physical function, and disease-specific quality of life 1.
Rehabilitation and Exercise
- Isometric quadriceps exercises can be started in the first week after surgery to reactivate the quadriceps muscles, provided they do not provoke pain 1.
- Concentric and eccentric exercises can be used to replace isometric exercises once the quadriceps is reactivated, as long as the knee does not react with effusion or pain 1.
- Neuromuscular training should be added to strength training to optimize outcome measurements 1.
Imaging and Diagnosis
- Imaging studies, such as ultrasound, can be used to evaluate quadriceps or patellar tendinopathy, postsurgical arthrofibrosis, and periarticular soft-tissue masses in patients with total knee arthroplasty 1.
- Dynamic ultrasound can be used to look for causes of snapping knee, including patellar clunk, snapping popliteus, and snapping related to component/liner malposition 1.
From the Research
Condition of the Quadriceps
The condition of the quadriceps can be affected by various factors, including anterior cruciate ligament (ACL) injury, quadriceps tendon rupture, and idiopathic fibrosis.
- Quadriceps weakness is common after ACL injury, especially in those who do not compensate well for the injury ("noncopers") 2.
- Atrophy and activation failure have been demonstrated in individuals with ACL injury, and these factors can account for quadriceps weakness 2.
- Quadriceps strength can change across the continuum of care in adolescent male and female athletes with ACL injury and reconstruction, with differences in recovery patterns between males and females 3.
- Quadriceps tendon rupture is a rare but serious injury that can lead to disability if not promptly recognized and treated 4.
- Idiopathic fibrosis of the quadriceps muscle is a condition characterized by progressive loss of knee flexion due to fibrosis within the muscle, and can be diagnosed with magnetic resonance imaging (MRI) and pathological findings 5.
- Quadriceps weakness after ACL reconstruction is a well-known phenomenon, and longstanding quadriceps weakness has been associated with suboptimal postoperative outcomes and the progression of radiographic knee osteoarthritis 6.
Factors Affecting Quadriceps Condition
Several factors can affect the condition of the quadriceps, including:
- ACL injury and reconstruction 2, 3, 6
- Quadriceps tendon rupture 4
- Idiopathic fibrosis of the quadriceps muscle 5
- Activation failure and atrophy 2
- Rehabilitation techniques and exercise methodologies 6
Rehabilitation and Treatment
Rehabilitation and treatment of quadriceps conditions can involve various approaches, including:
- Surgical treatment for quadriceps tendon rupture 4
- Rehabilitation techniques that address activation deficits and atrophy 2
- Exercise methodologies for restoring quadriceps size and strength after ACL reconstruction 6
- Z-plasty and release of fibrotic muscles for idiopathic fibrosis of the quadriceps muscle 5