Hip muscle strength explains only 11% of the improvement in HAGOS with an intersegmental approach to successful rehabilitation of athletic groin pain

Key points

1. 01Athletes with athletic groin pain returned to play in an average of 9.8 weeks with an 86% success rate
2. 02Hip strength and single-leg reactive strength deficits (large effect sizes at baseline) resolved fully after rehabilitation
3. 03Changes in hip abduction and external rotation strength explained only 11% of the variance in HAGOS Sports and Recreation scores
4. 04HAGOS improvements were sustained or further increased up to 6 months after return to play
5. 05No significant interlimb asymmetries were found in the injury group, suggesting bilateral deficits rather than side-to-side imbalance

How it was conducted

Design

Prospective cohort study with pre- to post-intervention testing; level of evidence 2

Participants

42 athletes with athletic groin pain (36 completed) and 36 matched uninjured controls; male, aged 18-35, multidirectional field-based sport

Intervention

Intersegmental control rehabilitation program across 3 levels (strength, linear running mechanics, change-of-direction mechanics), supervised approximately every 14 days

Outcome measures

Isometric hip strength (handheld dynamometry), single- and double-leg reactive strength index (drop jump), HAGOS subscales, Marx Activity Rating Scale

Follow-up

HAGOS collected at return to play, 3 months, and 6 months after return to play

Primary analysis

Linear regression with recursive feature elimination and 5x3-fold nested cross-validation to predict change in HAGOS Sports and Recreation subscale

What they found

• 36 of 42 athletes met return-to-play criteria; mean return-to-play time 9.8 +/- 3.0 weeks
• At baseline, AGP group had significantly lower HAGOS across all subscales vs controls (r = -0.74 to -0.89, P < .001)
• At baseline, isometric hip strength was lower in AGP vs CON for 5 of 6 groups: ABD d = -1.20, ADD d = -1.20, FLEX d = -1.07, EXT d = -0.83, ER d = -0.67 (all P <= .03)
• Single-leg drop jump RSI was lower in AGP vs CON at baseline (d = -0.73, P = .014)
• After rehabilitation, all 5 peak hip torque measures improved with large effect (d = -0.83 to -1.15, P < .001); SLDJ RSI showed a small increase (d = -0.30, P = .093)
• At return to play, no significant differences remained in hip strength or reactive strength vs controls
• HAGOS Sports and Recreation improved from median 54.7 at baseline to 85.9 at return to play (P < .001, r = -0.60)
• From RTP to 3 months, HAGOS Physical Activity (P < .001, r = -0.45) and Quality of Life (P = .008, r = -0.32) significantly increased
• At 6 months after RTP, 5 of 6 HAGOS subscales remained significantly lower than controls (P < .003, r = -0.35 to -0.51)
• Hip abduction and external rotation changes in a linear regression model explained 11% of variance in the HAGOS Sports and Recreation subscale change (no individual correlation reached significance: ABD P = .59 r = 0.32, ER P = .561 r = -0.10)

Limitations

• No true control group receiving no intervention or sham treatment, so spontaneous recovery cannot be excluded
• Uninjured controls were tested only at baseline, preventing comparison of natural strength changes over time
• Rehabilitation adherence was not measured, so variation in exercise volume and intensity cannot be accounted for
• Only male athletes were included, limiting generalizability to female athletes with athletic groin pain

Why it matters

For patients

Athletes with groin pain can expect to return to sport in roughly 10 weeks with this program and maintain their gains for at least 6 months, though some hip and groin function may still trail that of uninjured peers.

For clinicians

Hip strength deficits resolve with intersegmental rehabilitation even without targeted adductor exercises, but strength gains alone do not drive recovery of sporting function, supporting a movement-control focus over isolated muscle strengthening.

For readers

This study challenges the assumption that hip strength is the primary driver of recovery in athletic groin pain and points toward intersegmental movement coordination as the more important rehabilitation target.