Manitoba Softball Season: The Elbow and Shoulder Issues We See Every May

Slo-pitch and fastball leagues across Manitoba are starting up this week. Diamonds are open at Charleswood, Whittier, John Blumberg, and across the suburbs. The first few weeks of softball season produce a predictable pattern of injuries at our clinic — almost all of them in the throwing arm, almost all of them preventable, and almost all driven by the same biomechanical reality: the throwing motion places the highest forces in the human body on tissues that haven't done much over a long winter.

Here's what we see every May, why it happens, and what to do about it.

What's loading the throwing shoulder and elbow

The overhead throw is one of the most demanding athletic motions ever measured. At late cocking, the shoulder hits roughly 180° of external rotation, with valgus torque at the elbow approaching 64 Nm in adult pitchers — close to the ultimate failure load of the ulnar collateral ligament under laboratory conditions¹. The body manages this through coordinated kinetic chain mechanics; when any link in that chain underperforms, the load doesn't disappear, it just goes somewhere else.

For most amateur softball players, the chain link that's underperforming in early May is the lower body and core. Hip mobility is restricted, thoracic rotation is limited, and the trunk hasn't fired through a high-velocity motion in months. The shoulder and elbow then take up the slack — and the slack arrives in the form of pain.

The four patterns we see in May

Medial elbow pain — the softball equivalent of "pitcher's elbow." Tenderness over the medial epicondyle and along the ulnar collateral ligament, often after a single long throwing session. In most amateur cases this is a flexor-pronator overuse picture rather than a UCL injury, but persistent symptoms, pain at rest, or any sense of instability deserve a careful exam².

Anterior shoulder pain. Often a long-head biceps or anterior labral irritation, occasionally an anterior internal impingement pattern. Common in players who've come back from winter with reduced thoracic mobility — the shoulder ends up trying to extend further at end-range cocking than it should.

Posterior shoulder pain at follow-through. Pain in the back of the shoulder at deceleration is often a posterior capsule and infraspinatus tendon overload. The deceleration phase is where most of the eccentric work happens, and the rotator cuff is often the least-prepared tissue for that demand in May.

Lateral elbow pain. Less common in throwers than in racquet sports, but it shows up in players who've added a lot of bat-swing volume early. We covered this presentation in our piece on tennis elbow — a useful read if the pain pattern doesn't fit a throwing-arm picture.

What actually prevents these

The single highest-yield intervention is graded exposure to throwing volume, starting earlier than people think. The throwing shoulder needs at least 4–6 weeks of progressively building volume to tolerate full-game throwing demand without overuse symptoms. Players who go from no throwing in March to full game throwing in their first week of May are doing the opposite of what tendon adaptation requires³.

The principle is the same as what drives load management in other sports: there are no bad throws, only too many too soon, and the acute-to-chronic ratio applies to throwing volume just as cleanly as to running mileage.

The second highest-yield intervention is prep work that addresses the upstream chain — hip and thoracic mobility, scapular stability, and posterior shoulder strength. The Thrower's Ten, the Advanced Thrower's Ten, and any of several established overhead-athlete exercise progressions cover the relevant bases⁴. Done two or three times a week for the four to six weeks before opening day, they reduce in-season elbow and shoulder symptoms meaningfully.

What to do if pain has already arrived

For acute medial elbow pain after a single hard outing, the first 48 hours follow the same pattern we wrote about in our piece on PEACE & LOVE — protect early, load progressively, avoid the temptation to immobilize for a week. For shoulder pain that's been creeping in over multiple games, the answer is rarely "rest"; it's usually a careful look at what's failing in the kinetic chain and a structured plan to reload appropriately.

The exception is any pain associated with instability, locking, mechanical symptoms in the elbow, or a sudden loss of velocity or accuracy. Those warrant a careful exam and sometimes imaging before the next outing.

The takeaway

Most softball-related arm injuries in Manitoba's May aren't traumatic. They're the predictable result of a body asked to produce high-velocity motion on insufficient prep. The fix isn't more rest after the fact — it's better load management before. If your throwing arm is already complaining a few weeks into the season, that's the kind of work we do here in Winnipeg, and the earlier in the season we see it, the cleaner the rehab tends to be.

References

1. Fleisig GS, Andrews JR, Dillman CJ, Escamilla RF. Kinetics of baseball pitching with implications about injury mechanisms. Am J Sports Med. 1995;23(2):233–239.
2. Cain EL Jr, Dugas JR, Wolf RS, Andrews JR. Elbow injuries in throwing athletes: a current concepts review. Am J Sports Med. 2003;31(4):621–635.
3. Lyman S, Fleisig GS, Andrews JR, Osinski ED. Effect of pitch type, pitch count, and pitching mechanics on risk of elbow and shoulder pain in youth baseball pitchers. Am J Sports Med. 2002;30(4):463–468.
4. Wilk KE, Yenchak AJ, Arrigo CA, Andrews JR. The Advanced Thrower's Ten Exercise Program: a new exercise series for enhanced dynamic shoulder control in the overhead throwing athlete. Phys Sportsmed. 2011;39(4):90–97.

Author: Dr. Michael Minenna D.C., B.Sc., SFMA, FMS — Boreal Spine & Sport, Winnipeg, Manitoba.