Practical Guide to Ulnar Collateral Ligament Assessment

Ulnar Collateral Ligament (UCL) injuries are a growing concern in throwing sports, and physiotherapists are seeing them with increasing frequency, especially in younger athletes.

Yet despite their prevalence, assessing a UCL injury is rarely straightforward. Symptoms can be vague, special tests can overlap with flexor-pronator pathology, and imaging findings don’t always match clinical presentation. This blog provides a refresher on UCL injury assessment, with some tips from an expert.

If you want to see exactly how an expert physio assesses and manages UCL injuries, watch Mike Reinold’s full Case Study HERE. With Case Studies you can step inside the minds of experts and apply their strategies to get better results with your patients. Learn more here.

Why are they becoming more common?

The UCL is put under high valgus load during throwing, and each pitch is stressful enough to tear the ligament on its own. This means athletes rely heavily on dynamic stability, particularly from the flexor-pronator mass, to protect the ligament during high-velocity throws.

 The major factors driving the increase in prevalence of UCL injuries, particularly in younger athletes, include the heightened emphasis on velocity in throwing sports and year-round throwing with maximal effort. Many athletes now practise and compete all year, giving the elbow little time to recover.

The case

The patient in this case is a 17-year-old right-handed high-school pitcher who presented with a few weeks of worsening medial elbow pain. He reported:

• No previous elbow issues
• No specific incident or acute “pop”
• Pain with gripping in the gym
• Pain preventing him from throwing
• No neurological symptoms

He reported having rested briefly before attempting to throw again, which quickly reproduced the pain. Interestingly, he had also seen a pitching coach recently who helped him improve his velocity, another clue pointing toward increased valgus load.

His x-ray was normal, and his MRI showed a partial proximal UCL tear with mild signal in the flexor digitorum superficialis.

Assessment of UCL injuries

The elbow is a complex joint to assess. With multiple overlapping structures confined to a relatively small space, identifying the exact source of pain can be challenging. However, there are a few key indicators to help you differentiate potential sources of pain.

When testing range of motion in a patient with a UCL injury, discomfort is usually felt at end-range in flexion and pronation, but movements like supination and full elbow extension are often well tolerated.

Palpation plays an important role in understanding which structures are involved. This typically includes assessing the medial epicondyle, the flexor-pronator tendon, and the UCL itself to identify tender or reactive areas.

Special tests should include valgus stress testing, along with assessment of the flexor-pronator mass, ulnar nerve, and relevant bony structures. Each of these tests provides insight into the integrity of the ligament and the involvement of surrounding tissues. See Mike demonstrate the special tests he uses in the below clip from his Case Study:

One useful test Mike employs to assess flexor-pronator involvement is what he refers to as the “thinker sign.” The patient presses firmly against the side of their head with their fingers, palm facing inward. Symptom reproduction during this maneuver can help gauge the contribution of the flexor-pronator muscles to the patient’s pain.

Findings

The patient presented with:

• Tenderness directly over the UCL
• Pain with passive external rotation, milking manoeuvre, and valgus testing
• Mild discomfort with flexor-pronator testing
• No symptoms on valgus extension overload
• No ulnar nerve signs

These findings aligned well with the MRI: a partial proximal UCL tear without bony or neurological involvement.

However, Mike emphasises that structural findings alone don’t guide treatment, understanding functional deficits will help him build a treatment plan. See Mike talk through the deficits he identified for his patient in the below video from his Case Study:

Non-surgical management

For most partial tears, conservative management is the first line of care.

Interestingly, the initial shutdown from throwing is largely the same regardless of injury severity: Six weeks with no throwing.

From there, Mike implements a four-phase approach:

• Phase 1 (Weeks 1–2): Facilitate healing
• Phase 2 (Weeks 3–4): Advance exercise progression
• Phase 3 (Weeks 5–6): Prepare to throw
• Phase 4 (Week 7+): Begin interval throwing program

CLINICAL PEARL: Mike explains that the earlier symptoms resolve during special testing, the better the expected outcome. For this reason, he recommends re-assessing clinical tests at 2, 4 and 6 weeks. If symptoms persist at 6 weeks, it’s appropriate to refer for a surgical review.

Wrapping up

Understanding how to identify UCL injuries and assess function thoroughly is fundamental to producing an effective management plan for these patients.

A detailed assessment not only confirms the presence of a UCL injury, but also highlights compensatory patterns, muscle involvement, and functional limitations that need addressing to ensure the patient can safely return to full play.

If you want to know how expert Mike Reinold rehabilitated his patient back to play, watch his full Case Study here.