Medication Recommendation for Chronic Generalized Musculoskeletal Stiffness
Neither baclofen nor tizanidine is appropriate for your condition, and you should not use either medication. 1, 2
Why Baclofen Is Not Indicated
Baclofen is FDA-approved exclusively for spasticity from upper motor neuron disorders (multiple sclerosis, spinal cord injury, cerebral palsy) and is explicitly not indicated for skeletal muscle problems from rheumatic or musculoskeletal disorders. 1
Your presentation—inability to sit cross-legged, touch toes, squat below knee level, or maintain upright posture—describes peripheral musculoskeletal stiffness and limited range of motion, not CNS-mediated spasticity. 2
Baclofen works via GABA-B receptor agonism to reduce CNS-driven spasticity; this mechanism does not address peripheral muscle tightness or joint restriction. 2
Prescribing baclofen for peripheral musculoskeletal tightness commonly produces muscle weakness (reported in 10-75% of patients), which will further impair your ability to sit, squat, and maintain posture. 2, 3
The American Geriatrics Society explicitly advises that baclofen may only be justified when muscle spasm is attributable to CNS pathology, which you do not have. 2
Why Tizanidine Is Also Not Appropriate
Tizanidine is a centrally acting alpha-2 adrenergic agonist designed to treat spasticity (velocity-dependent increase in muscle tone with hyperreflexia), not chronic musculoskeletal stiffness. 4, 5
While tizanidine has demonstrated efficacy in 8 trials for acute low back pain (typically 2-week courses), it has no evidence base for chronic generalized musculoskeletal stiffness lasting many years. 2, 4
The American College of Physicians recommends tizanidine only for short-term relief (7-14 days maximum) of acute pain, not for chronic conditions. 2
Your symptoms—inability to achieve specific positions due to what you describe as "bones, ligaments locks"—suggest structural or connective tissue restrictions rather than increased muscle tone that would respond to a centrally acting muscle relaxant. 2
Why Combination Therapy Is Inappropriate
Combining baclofen and tizanidine has been studied only in the context of true spasticity from neurological disease, not peripheral musculoskeletal stiffness. 6, 7
A pharmacokinetic study confirmed that tizanidine and baclofen can be safely combined without drug interactions, but this was evaluated specifically for spasticity control in neurological conditions. 7
Both drugs work through central mechanisms (GABA-B agonism and alpha-2 agonism) that do not address the peripheral biomechanical restrictions you describe. 5, 2
Combining these agents would increase your risk of sedation (2-fold increase in CNS adverse events), muscle weakness, and hypotension without addressing the underlying problem. 2, 4
What You Actually Need
Your presentation strongly suggests a structural or connective tissue disorder requiring proper diagnostic evaluation, not empiric muscle relaxant therapy.
Conditions to consider include:
- Ankylosing spondylitis or other seronegative spondyloarthropathies
- Diffuse idiopathic skeletal hyperostosis (DISH)
- Ehlers-Danlos syndrome or other connective tissue disorders
- Severe myofascial restriction requiring specialized manual therapy
- Structural hip or spine pathology limiting range of motion
You need rheumatologic evaluation, spine imaging (X-ray, possibly MRI), and assessment by a physical medicine specialist before any pharmacologic intervention. The fact that "strength is there but bones, ligaments locks" is a critical clue that this is not a muscle tone problem amenable to muscle relaxants.
Critical Pitfall to Avoid
The most dangerous error would be to mask your symptoms with sedating medications while missing a progressive structural or inflammatory condition that requires specific treatment. 2, 1 Starting baclofen or tizanidine empirically will expose you to significant adverse effects (weakness, sedation, falls risk) without addressing—and potentially delaying diagnosis of—the true underlying pathology.