Case Study: Runner’s Pain

Our Patient

Our patient is a 33 year-old female runner complaining of hamstring and calf tightness, and posterior knee pain in both legs. The pain began in 2015, but she continued to run. 

The Challenge

The patient had  seen numerous running physical therapists and had undergone multiple gait analyses without any results. Five years prior she had sustained tears in the medial collateral ligament (MCL) and  posterior cruciate ligament (PCL) in the right knee when windsurfing. 

Our Diagnostic Approach

3D Gait Analysis

We conducted a 3D gait analysis using advanced technologies and proprietary software to get an objective picture of the patient’s gait mechanics. Gait analysis results revealed multiple issues: 

• Excessive pronation bilaterally, worse on the left
• Left foot crossover.
• Oversupination on push-off
• Low rear push-off bilaterally
• Bilateral varus (bow-legged) thrust, worse on the right
• Limited hip extension bilaterally
• Excessive pelvic rotation
• Excessive vertical oscillation
• Weakened pretibial muscles bilaterally
• Bilateral pelvic drop, worse on the right
• External tibial rotation on the left
• Entire left leg has excessive internal rotation, most likely a compensation pattern from unloading of the right leg
• Low cadence (steps per minute), increasing ground reaction forces
• Greater right foot ground contact 

Clinical Exam

We conducted a battery of tests and assessments to evaluate posture and biomechanics. We determined that the patient:

• Had an excessive Q angle while standing – the angle between a line extending from the top of the anterior iliac bone and the midpoint of the patella, and a line from the midpoint of the patella to the tibial tuberosity.  
• Had noticeable bilateral tibial varum (bowing). 
• Failed to load her medial arches and big toes, especially on the left. 
• Had an inverted left foot. 
• Had bilateral raised 1st metatarsals. 
• Had bilateral varus thrust during running.
• Compensated for right knee pain by slight flexion during heel strike.
• Had a positive slump test on the right side.
• We elicited Tinel’s sign (pins-and-needles) by palpating the tibial nerve where it passes through the popliteal fossa – a diamond-shaped space behind the knee joint.
• Manual palpation of the popliteal fossa and the calf revealed loss of popliteal and crural fascia gliding.

Ultrasound Imaging of the Right Knee

We used high-resolution diagnostic ultrasound to visualize the patient’s right knee: 

• We found a mild suprapatellar effusion, with slight wear of the trochlear cartilage. indicating mild chondromalacia – erosion of the hyaline cartilage. 
• There was excessive movement of the posterior cruciate ligament (PCL) during dynamic knee extension. 
• The right popliteus muscle had hypertrophied and its fascia had thickened. 
• The posterior oblique and popliteal oblique ligaments and the joint capsule were hyperechoic and appeared to be thickened. 
• There was reduced neural dynamic motion between the tibial and peroneal branches of the sciatic nerve during dynamic plantarflexion.
• The tibial nerve appeared larger than normal, with a thickened perineurium, and responded positively to sono palpation compared to the left side.

Our Diagnosis

Mechanical

• Bilateral dynamic thrust was worse on the right leg
• There was posterior-lateral instability of the right knee

Neurogenic

• We identified dynamic neurogenic entrapment of the tibial nerve
• We noted abnormal sciatic nerve mechanics

Soft tissues

• Fascial distortion was affecting the entire lower posterior chain

Discussion

When conducted by an experienced clinician who can clinically interpret results, 3D gait analysis can be an extremely useful tool. However, even the most advanced gait analysis system cannot always explain the reasons for mechanical deficits. The data produced tells us what is wrong, but we still have to figure out the underlying cause, and differentiate compensation patterns from pathology. Diagnosis requires clinical experience, and expertise with other diagnostic tools such as high resolution diagnostic ultrasonography.