Muscle Relaxant Recommendation for a 23-Year-Old Athlete with Mild Hip Pain
For a 23-year-old athlete with mild hip pain from strenuous activity, I do not recommend prescribing a muscle relaxant at all. Instead, prioritize physiotherapist-led treatment including exercise, education, and activity modification, with paracetamol (up to 4 g/day) as first-line pharmacologic therapy if needed 1.
Why Muscle Relaxants Are Not Indicated
Hip-related pain in young active adults is primarily managed non-pharmacologically, with consensus recommendations from the International Hip-related Pain Research Network emphasizing physiotherapist-led treatment as the cornerstone of care 1.
Muscle relaxants have no established role in hip-related pain in young athletes, as the evidence base for these agents is limited to acute back or neck pain from peripheral musculoskeletal conditions, not hip pathology 2, 3.
The most common hip conditions in young active adults—femoroacetabular impingement (FAI) syndrome, acetabular dysplasia, and labral/chondral pathology—require comprehensive assessment and targeted rehabilitation rather than muscle relaxation 1.
First-Line Management Approach
Non-Pharmacological Treatment (Highest Priority)
Exercise therapy is strongly recommended for hip-related pain in young active adults, with expert consensus rating this 9/9 despite limited direct evidence, as physical activity is critical for health and return to sport 1.
Physiotherapist-led treatment should include hip muscle strengthening, dynamic balance training, single-leg squat alignment correction, and sport-specific functional tasks tailored to her athletic goals 1.
Patient education and shared decision-making received unanimous expert consensus (9/9 rating), emphasizing discussion of treatment options, expected outcomes, and return-to-sport expectations 1.
Pharmacologic Management (If Needed)
Paracetamol (acetaminophen) up to 4 g/day is the oral analgesic of first choice for mild-to-moderate pain due to its efficacy and safety profile, with an effect size of 0.21 for pain relief and number needed to treat of 4 1.
NSAIDs at the lowest effective dose should be added only if paracetamol provides inadequate relief, as they are equally effective as muscle relaxants for musculoskeletal pain with fewer adverse effects 4, 2.
If a Muscle Relaxant Is Absolutely Required (Not Recommended)
Should you decide against evidence-based guidelines to prescribe a muscle relaxant despite lack of indication:
Cyclobenzaprine 5 mg Three Times Daily
Cyclobenzaprine 5 mg TID is as effective as 10 mg TID with significantly lower incidence of sedation (the most common adverse effect), demonstrated in two randomized controlled trials enrolling 1,405 patients 5, 6.
Onset of relief occurs within 3-4 doses of the 5 mg regimen, with efficacy independent of sedation based on subanalysis of responders 6.
Critical warnings: Cyclobenzaprine has significant anticholinergic effects (dry mouth, drowsiness, confusion, urinary retention), is structurally similar to tricyclic antidepressants, and acts as a potent non-competitive histamine H1 receptor antagonist causing sedation in >30% of patients 7, 5, 8.
Agents to Avoid
Do not prescribe carisoprodol: It is a Schedule II controlled substance with "substantial barbiturate-like biological action," high abuse and diversion potential, and severe withdrawal symptoms including hallucinations and seizures 4.
Do not prescribe benzodiazepines (diazepam): These carry substantial risks of tolerance, addiction, depression, cognitive impairment, and 50% higher total adverse events compared to placebo, with no superiority over other muscle relaxants 9, 4.
Do not prescribe baclofen: It is not indicated for routine musculoskeletal pain, being primarily an antispasticity agent for upper motor neuron syndromes 7.
Critical Clinical Pitfalls
All muscle relaxant trials were ≤2 weeks duration, and these agents should only be used short-term with insufficient evidence for chronic use in any musculoskeletal condition 7, 2.
Muscle relaxants do not enhance clinical effect of analgesics in acute musculoskeletal conditions, and combination therapy increases side effect burden (primarily drowsiness) without proven additive benefit 5, 3.
For this athlete, prescribing a muscle relaxant risks sedation that impairs training and performance, contradicting the goal of return to sport at preinjury level 1.
Return-to-Sport Considerations
Physical activity and sport participation should be maintained during treatment, with gradual progression from basic athletic movements to sport-specific high-level tasks including running, twisting, and moving into provocative positions 1.
Monitor using validated outcome measures: Copenhagen Hip and Groin Outcome Score (HAGOS) or International Hip Outcome Tool (IHOT), along with hip muscle strength, range of motion, and functional task performance 1.
Return-to-sport should follow a continuum: return to participation → return to sport → return to performance (at or above preinjury level), with only 17-25% of athletes achieving optimal preinjury performance after hip interventions 1.