Stiff knee gait describes a walking pattern with limited knee bend or extension during movement. This altered motion impacts mobility and interferes with daily activities. The condition affects how a person moves their leg, often leading to compensatory movements. It signals an underlying issue restricting natural walking mechanics.
Understanding Stiff Knee Gait
Stiff knee gait involves reduced or delayed knee flexion during the swing phase of walking, when the leg lifts and moves forward [2.1, 2.2]. Normally, the knee bends to allow the foot to clear the ground and prepare for the next step. In stiff knee gait, this bend is diminished, often resulting in peak knee flexion during swing of less than 50 degrees, compared to a typical 45-65 degrees [2.2].
Limited knee motion can lead to compensatory strategies to prevent foot dragging, such as ipsilateral hip circumduction (where the leg swings out in a semicircle) or contralateral vaulting (where the person elevates the opposite hip) [1.1, 2.2]. Reduced knee flexion also impacts stride length and walking efficiency, increasing energy expenditure [1.1, 2.2]. This biomechanical issue often involves an inability to adequately clear the foot during the swing phase, increasing the risk of tripping and falling [2.1, 3.1].
Common Causes of Stiff Knee Gait
Medical conditions, injuries, and post-surgical factors can contribute to stiff knee gait. Arthritis, including osteoarthritis and rheumatoid arthritis, causes inflammation and structural changes within the knee joint, leading to pain and reduced range of motion. These changes can impede the smooth bending and straightening of the knee during walking [4.4].
Post-surgical complications, especially after knee replacement (arthroplasty) or other knee surgeries, are common causes. Scar tissue formation, inadequate rehabilitation, or improper alignment of prosthetic components can restrict knee movement [4.4]. For instance, a stiff knee after replacement can result from a fibrotic response, limiting joint flexibility.
Neurological conditions affect muscle control and coordination. Conditions like stroke, cerebral palsy, and multiple sclerosis can lead to muscle spasticity or weakness [2.1, 2.5]. Stiff knee gait is common in stroke survivors, affecting about 60% of those with gait impairments [1.1, 2.1]. While quadriceps femoris overactivity (especially the rectus femoris) was long considered a primary cause in stroke patients, recent research suggests inadequate ankle push-off is a more frequent underlying factor, accounting for about 74% of cases compared to rectus femoris spasticity at 19% [2.4, 3.3, 4.2, 4.4, 5.5].
Muscle imbalances, including weakness or spasticity, contribute to altered muscle tone around the knee [1.1, 2.5]. For example, spasticity in the ankle plantar flexors can force the ankle into plantar flexion and the knee into hyperextension, limiting knee flexion during the swing phase [1.1, 2.5]. Direct trauma or injury to the knee joint, ligaments, or surrounding tissues can also result in restricted movement and lead to stiff knee gait [4.4].
How Stiff Knee Gait is Diagnosed
Healthcare professionals use several methods to identify and assess stiff knee gait, starting with a thorough physical examination. During this, the clinician evaluates the knee’s active and passive range of motion, assesses muscle strength, and palpates the area for tenderness or swelling [4.4]. This hands-on assessment helps pinpoint areas of restriction and pain.
Gait analysis is a central diagnostic component, involving careful observation of the individual’s walking pattern [4.4]. This ranges from simple visual assessment to sophisticated methods using specialized equipment like motion capture systems or pressure plates. These tools provide detailed data on joint angles, stride length, and ground reaction forces, offering objective insights into the biomechanical deviations of stiff knee gait [4.1, 4.4]. For instance, measurements like peak knee flexion during swing and knee range of motion from toe-off to peak knee flexion are useful in identifying the condition in stroke survivors [1.4].
Imaging studies view the knee’s internal structures. X-rays can reveal bone spurs or joint space narrowing indicative of arthritis [4.4]. Magnetic Resonance Imaging (MRI) or Computed Tomography (CT) scans offer detailed images of soft tissues like ligaments, tendons, and cartilage, helping identify issues such as scar tissue, meniscal tears, or other structural damage contributing to stiffness [4.4]. A comprehensive patient history is also important. This includes discussing symptoms, past medical conditions, previous injuries, and any surgical interventions, providing context for the observed gait pattern and guiding further diagnostic steps [4.4].
Treatment and Management Strategies
Addressing stiff knee gait often involves a multi-faceted approach, with physical therapy as a primary intervention. Physical therapists design exercises to improve the knee’s range of motion, targeting both flexion and extension [4.4]. These exercises also strengthen surrounding muscles like the quadriceps and hamstrings, and improve overall balance and coordination. Manual therapy techniques, where a therapist uses hands-on methods to mobilize the joint and soft tissues, can also increase flexibility [4.4].
Assistive devices support mobility and reduce knee strain. Braces may provide stability or guide the knee through a more natural range of motion. Crutches or walkers can reduce weight-bearing on the affected limb, allowing safer, more comfortable movement, especially during initial recovery or for individuals with significant limitations [4.4].
Medications manage symptoms associated with stiff knee gait. Over-the-counter pain relievers like ibuprofen or acetaminophen can reduce pain and inflammation [4.4]. Prescription anti-inflammatory drugs or muscle relaxants may also be prescribed to alleviate discomfort and reduce muscle spasticity [4.4]. Injections directly into the knee joint can provide relief. Corticosteroid injections reduce inflammation and pain, while hyaluronic acid injections may lubricate the joint, improving smooth movement [4.4].
For severe or persistent cases, surgical interventions may be considered. Procedures like arthroscopy can remove scar tissue or other obstructions limiting knee movement [4.4]. Manipulation under anesthesia involves gently bending and straightening the knee while sedated to break up adhesions and restore range of motion [4.4]. If previous knee surgeries caused stiff knee gait, revision surgeries may be necessary to correct underlying issues or improve prosthetic function [4.4]. Consistent home exercises and adaptations to daily activities are also encouraged to maintain progress and support long-term management [4.4].