The tissue that makes up your structure
The musculoskeletal system is not one tissue. It is a hierarchy of connected tissues with different compositions, different turnover rates, different vascular supplies, and different biochemical requirements. Understanding which tissue is the problem — and what that tissue needs to function, repair, and tolerate load — is the starting point for a biochemically-informed approach to musculoskeletal health.
Primary substrate: Creatine phosphate (explosive), glycogen (sustained), fatty acids (endurance)
Repair rate: Fast — satellite cells activated within hours of damage
Key nutrients: Creatine, protein (leucine threshold), magnesium, B vitamins, carnosine
Failure mode: Sarcopenia (ageing), rhabdomyolysis (overload), contracture (chronic shortening)
Primary structure: Type I collagen (tendons), mixed Type I/III collagen (ligaments)
Repair rate: Slow — poor vascular supply, weeks to months for meaningful remodelling
Key nutrients: Glycine, proline, vitamin C, copper, silicon, zinc
Failure mode: Tendinopathy — failed healing response, not inflammation as previously thought
Primary structure: Type II collagen + aggrecan proteoglycan + water (70% by weight)
Repair rate: Extremely slow — avascular, relies on synovial fluid diffusion
Key nutrients: Glycine, proline, vitamin C, glucosamine, chondroitin, omega-3
Failure mode: Osteoarthritis — progressive matrix degradation exceeding synthesis
Primary structure: Type I and III collagen with contractile myofibroblasts — fascia actively contracts
Repair rate: Moderate — better vascularised than tendons, slower than muscle
Key nutrients: Collagen precursors, magnesium (myofibroblast relaxation), omega-3
Failure mode: Fibrosis, adhesions, plantar fasciitis, frozen shoulder
Primary structure: Synovial membrane producing hyaluronic acid — the joint's lubricating fluid
Repair rate: Moderate — membrane is vascularised but HA production declines with age and inflammation
Key nutrients: Omega-3 (reduces inflammatory cytokines in synovial fluid), vitamin D, glucosamine
Failure mode: Inflammatory arthritis — immune-mediated synovial destruction
Primary structure: Myelin sheath (phospholipid) surrounding axons — myelin requires B12, choline, omega-3
Repair rate: Slow — 1–4mm per day of axon regrowth after injury
Key nutrients: B12 (methylcobalamin), B6, alpha-lipoic acid, omega-3, magnesium
Failure mode: Peripheral neuropathy, nerve entrapment, referred pain patterns
Creatine — far beyond sport
Creatine monohydrate is the most studied sports supplement in history. It is also one of the most misframed. The popular understanding — creatine makes you stronger and helps you lift more — is true but incomplete. The underlying mechanism reaches far beyond muscle performance into mitochondrial function, neurological health, bone density, and biological ageing.
Creatine — the full clinical picture
Seven systems, one molecule
Creatine is a guanidino compound synthesised from arginine, glycine, and methionine — primarily in the liver and kidneys. It is stored in muscle (95%) and brain (5%) as phosphocreatine, the most rapidly available energy buffer the body has. The phosphocreatine system replenishes ATP in milliseconds — faster than glycolysis or oxidative phosphorylation. This is the mechanism behind explosive strength. But phosphocreatine turnover matters in every high-energy tissue, not just contracting muscle.
Musculoskeletal
Explosive power and muscle mass
Replenishes phosphocreatine for maximal effort contractions. Increases training volume capacity. Promotes satellite cell activation and muscle protein synthesis. The most evidence-backed intervention for preserving muscle mass in ageing.
Mitochondrial
Energy buffer across all tissues
Phosphocreatine buffers ATP in mitochondria-rich tissues including cardiac muscle and neurons. Supports mitochondrial efficiency under high metabolic demand. Relevant for any tissue where energy supply is the limiting factor.
Neurological
Cognitive function and neuroprotection
The brain stores approximately 5% of body creatine. Supplementation increases brain creatine measurably on MRS. Associated with improved working memory, processing speed, and executive function — particularly under sleep deprivation and cognitive load. Emerging evidence for neuroprotection in TBI and neurodegenerative disease.
Skeletal
Bone density support
Creatine supplementation alongside resistance training is associated with improved bone mineral density in postmenopausal women in RCT data. The mechanism involves increased mechanical loading through greater training capacity and possible direct effects on osteoblast activity.
Metabolic
Insulin sensitivity and glucose
Creatine increases GLUT4 transporter expression in muscle, improving insulin-stimulated glucose uptake. Clinically relevant for insulin resistance presentations where improving skeletal muscle glucose disposal is a therapeutic target alongside dietary and lifestyle intervention.
Anti-ageing
Carnosine and cellular protection
Creatine is structurally related to carnosine — both are guanidino compounds synthesised from similar precursors. High dietary creatine intake from meat sources correlates with carnosine status. Carnosine buffers muscle acid, chelates heavy metals, and has anti-glycation effects in both muscle and neural tissue.
On creatine dosing and form
Creatine monohydrate is the only form with the full evidence base. Other forms — creatine ethyl ester, buffered creatine, creatine HCl — have not demonstrated superiority in well-controlled trials and cost significantly more. Standard protocol: 3–5g daily, taken consistently without loading phase (loading accelerates saturation but produces no additional long-term benefit). Take with food. No need to cycle. Creatine is safe at 3–5g daily in healthy adults — the kidney concern is a persistent myth not supported by evidence in people with normal renal function. Those with existing kidney disease should discuss with their GP before supplementing.
Collagen synthesis — the structural repair pathway
Collagen is the most abundant protein in the body — approximately 30% of total protein mass. It is the primary structural component of tendons, ligaments, cartilage, bone matrix, fascia, skin, and the walls of blood vessels. The ability to synthesise and remodel collagen determines whether structural tissue repair keeps pace with damage — and whether ageing produces progressive structural deterioration or not.
Collagen synthesis is not simply a matter of eating protein. It is a multi-step enzymatic pathway with specific cofactor requirements that are frequently insufficient in people with musculoskeletal problems.
Collagen Synthesis Pathway
From amino acids to structural matrix — and where the process fails
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Step 1: Substrate availability. Collagen is approximately 33% glycine, 11% proline, and 10% hydroxyproline by amino acid content. Dietary glycine from bone broth, connective tissue, and skin provides the most concentrated source. Glycine is conditionally essential — endogenous synthesis from serine is insufficient to meet collagen repair demands, particularly under chronic injury or in older adults. Glycine · Proline · Hydroxyproline
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Step 2: Hydroxylation. Prolyl hydroxylase and lysyl hydroxylase convert proline and lysine to hydroxyproline and hydroxylysine — the cross-linking amino acids that give collagen its tensile strength. Both enzymes require vitamin C as an essential cofactor. Vitamin C deficiency does not produce scurvy immediately — it first impairs collagen quality long before clinical signs appear. Vitamin C (ascorbic acid)
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Step 3: Triple helix formation. Three pro-collagen chains wind into the characteristic triple helix — the source of collagen's extraordinary tensile strength. This process requires appropriate temperature, pH, and the presence of specific chaperone proteins. Magnesium is required for procollagen processing enzyme activity. Magnesium
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Step 4: Cross-linking. Lysyl oxidase — a copper-dependent enzyme — catalyses the cross-linking of collagen fibres into the mature matrix that provides structural integrity. Copper deficiency impairs this step. Low copper → inadequate cross-linking → structurally weak collagen regardless of how much collagen precursor is available. Copper (via lysyl oxidase)
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Step 5: Matrix remodelling. Matrix metalloproteinases (MMPs) degrade old or damaged collagen while fibroblasts synthesise new matrix. This remodelling process responds to mechanical load — tissue stressed appropriately within its tolerance strengthens; tissue stressed excessively degrades. Zinc is required for MMP activity. Omega-3 modulates the inflammatory signals that regulate fibroblast activity. Zinc · Omega-3 · Mechanical load
Tissue tolerance — the concept that changes how you think about injury
Tissue tolerance — the key clinical concept
Injury is not an event. It is the cumulative consequence of load exceeding tolerance.
Every tissue has a tolerance threshold — the amount of mechanical, chemical, and thermal stress it can absorb before structural or functional failure occurs. Below the threshold, appropriate loading drives adaptation: tendons thicken, muscle hypertrophies, bone density increases, cartilage matrix is maintained. Above the threshold, damage accumulates faster than repair — and if this continues long enough, the tissue eventually fails. The clinical insight from tissue tolerance is that injury is almost never caused by a single event. The person who "throws their back out" lifting a bag of shopping did not injure themselves lifting the bag. The bag was the last load in a long series of sub-threshold insults that progressively eroded the tissue's reserve capacity until the margin was gone. The bag was the straw. The back had been loading toward failure for months or years. The same logic applies to tendinopathy, osteoarthritis, stress fractures, and rotator cuff tears. The acute event gets the diagnosis. The chronic loading history is the actual cause. Addressing the acute event without addressing the loading history and the biochemical environment that allowed it to develop is addressing the symptom, not the problem.
The Janda model — why muscles fail in predictable patterns
Vladimir Janda's Muscle Classification
Tonic muscles shorten. Phasic muscles lengthen. The pattern is predictable — and biochemically reinforced.
Tonic muscles — tend to shorten and become facilitated under stress
Hip flexors (iliopsoas)
Upper trapezius
Pectorals (major and minor)
Hamstrings
Piriformis
Suboccipital muscles
Quadratus lumborum
Levator scapulae
Phasic muscles — tend to lengthen and become inhibited under stress
Gluteus maximus
Deep neck flexors
Rhomboids and middle trapezius
Vastus medialis
Serratus anterior
Lower abdominals
Tibialis anterior
Peroneals
Janda's model matters clinically because it predicts where musculoskeletal dysfunction will develop before it becomes painful. Shortened hip flexors from prolonged sitting inhibit their antagonists — the glutei. Inhibited glutei fail to control hip extension, placing excessive demand on the lumbar erectors and hamstrings. Overloaded hamstrings develop tendinopathy or strain. The site of pain — the hamstring — is not the site of the problem — the hip flexor/glute relationship. Treating the hamstring without addressing the hip flexor shortening is treating downstream of the problem.
The biochemical dimension adds a layer Janda's anatomical model cannot address. Magnesium deficiency maintains tonic muscle hypertonicity — magnesium is required for muscle relaxation (calcium induces contraction, magnesium induces relaxation). A chronically tight upper trapezius in someone with low magnesium will not respond adequately to manual therapy or stretching because the biochemical driver of the tension is unaddressed. Vitamin D deficiency impairs muscle function at the fibre level — low vitamin D is associated with muscle weakness, pain, and reduced force production independent of any structural or movement problem. Omega-3 deficiency maintains synovial inflammation that perpetuates joint stiffness and pain regardless of movement quality.
The ascending pain sensitisation pathway — why chronic pain is a nervous system story
Pain Sensitisation Cascade
From tissue nociception to central sensitisation — why the pain outlasts the injury
1
Peripheral nociception
Tissue damage activates nociceptors — pain-sensing nerve endings. Inflammatory mediators (prostaglandins, bradykinin, substance P) lower the nociceptor threshold, producing hyperalgesia (increased pain sensitivity) at the injury site. This is the appropriate acute response — it protects the tissue from further loading.
2
Spinal sensitisation
Repeated peripheral nociceptive input sensitises dorsal horn neurons in the spinal cord — a process called wind-up. The synaptic threshold lowers. Stimuli that previously produced no pain now produce pain. The pain begins to spread beyond the original injury site as adjacent spinal segments become sensitised.
3
Central sensitisation
With prolonged input, central pain processing changes at the brain level. The anterior cingulate cortex and insula — areas involved in pain's emotional and cognitive dimensions — become hyperactivated. Pain becomes less about tissue state and more about nervous system state. Non-painful stimuli (light touch, temperature) produce pain. This is allodynia — and it explains why chronic pain persists long after tissue healing has occurred.
4
The 10,000-hour movement engram
Motor patterns are learned through repetition — thousands of movement repetitions groove neural pathways that become automatic. A movement pattern performed with faulty loading mechanics over years produces two problems simultaneously: cumulative tissue damage from the loading, and a deeply entrenched motor engram that perpetuates the faulty pattern even after awareness and intent to change. This is why motor re-education requires more than instruction — it requires thousands of correctly-loaded repetitions to overwrite the established pattern. Pain inhibits motor activation and further entrenches compensatory patterns. The cycle is: faulty loading → tissue damage → pain → motor inhibition → more faulty loading.
5
The biochemical amplifier
Systemic inflammation amplifies pain sensitisation at every level of the cascade. Inflammatory cytokines (IL-6, TNF-alpha) lower nociceptor thresholds, increase spinal sensitisation, and impair descending pain inhibition from the periaqueductal grey. A client with chronic musculoskeletal pain and elevated hsCRP is not just inflamed — their inflammatory state is actively maintaining and amplifying their pain experience. Addressing the systemic inflammation is addressing the pain, not just treating the tissue.
The nutritional foundations of musculoskeletal health
| Nutrient |
Evidence |
Mechanism |
Clinical priority |
| Creatine monohydrate |
Strong |
Phosphocreatine replenishment for explosive ATP production, satellite cell activation, muscle protein synthesis, cognitive protection |
3–5g daily. Priority for anyone losing muscle mass, anyone over 45, anyone in athletic training |
| Glycine |
Strong |
Primary structural amino acid in collagen — 33% of collagen sequence. Conditionally essential — endogenous synthesis insufficient for repair demands |
Bone broth, skin, collagen hydrolysate supplement. 5–10g pre-sleep supports collagen synthesis during overnight repair phase |
| Vitamin C |
Strong |
Cofactor for prolyl and lysyl hydroxylase — essential for collagen cross-linking and tensile strength. Antioxidant in synovial fluid. Depleted by infection, stress, smoking |
500–1,000mg daily in divided doses. Food sources: kiwi, bell pepper, citrus. Assess on Metabolomix+ OAT |
| Omega-3 (EPA+DHA) |
Strong |
Reduces prostaglandin E2 and leukotriene B4 in synovial fluid, reducing joint inflammation. Supports membrane fluidity in chondrocytes. Modulates fibroblast activity in connective tissue repair |
2–3g EPA+DHA daily. Anti-inflammatory effect dose-dependent. Take with largest meal for absorption |
| Magnesium |
Strong |
Required for muscle relaxation (calcium contracts, magnesium relaxes). Cofactor for 300+ enzymes including ATP synthesis and protein synthesis. Reduces muscle hypertonicity, cramps, and night spasms |
300–400mg elemental daily as glycinate or malate. Glycinate preferred for muscle relaxation and sleep. Assess serum magnesium — functional optimal 0.85–0.95 mmol/L |
| Vitamin D |
Strong |
VDR in muscle fibres — vitamin D directly regulates muscle protein synthesis, type II fast-twitch fibre function, and muscle force production. Deficiency produces myopathy, weakness, and diffuse musculoskeletal pain |
Target 100–150 nmol/L on 25-OH-D. Dose accordingly — typically 2,000–4,000 IU D3 plus K2 (100mcg MK-7) |
| Copper |
Good |
Required for lysyl oxidase — the enzyme that cross-links collagen fibres into the mature matrix. Copper deficiency produces structurally weak connective tissue regardless of collagen precursor availability |
Liver once weekly provides adequate copper. Supplementation if serum copper below optimal. Avoid high-dose zinc without copper — zinc and copper compete for absorption |
| Collagen hydrolysate |
Good |
Hydrolysed collagen provides glycine, proline, and hydroxyproline in a pre-digested form that reaches connective tissue. RCT data supports joint pain reduction and cartilage synthesis markers |
10–15g daily. Take with vitamin C for hydroxylation cofactor. Best timing: 30–60 minutes before exercise or at night during repair phase |
The person whose back goes into spasm every few months, who takes two weeks off, recovers, and then repeats the cycle six months later is not unlucky. They are operating at or near their tissue tolerance limit, in a biochemical environment that is insufficient for adequate repair, with a motor pattern that perpetuates the loading that caused the problem. Addressing any one of these three without the others is addressing a third of the problem.
What functional testing adds to the musculoskeletal picture
Most musculoskeletal presentations are assessed through imaging (X-ray, MRI, ultrasound) and clinical examination. What these do not assess is the biochemical environment in which the tissue is trying to function and repair. Vitamin D deficiency producing genuine myopathy can mimic fibromyalgia, non-specific low back pain, and generalised joint pain — and resolves completely with normalisation of vitamin D. Magnesium insufficiency producing chronic muscle hypertonicity is treated with manual therapy and stretching that provides temporary relief until the magnesium level is addressed. Systemic inflammation elevating the pain sensitisation threshold means manual therapy, exercise, and analgesics are working against a headwind that the anti-inflammatory picture could resolve.
The Randox blood chemistry panel covers vitamin D, magnesium, hsCRP, ferritin (iron for myoglobin), and CK (creatine kinase — an indicator of muscle stress and damage). The Metabolomix+ OAT covers vitamin C (ascorbic acid), B vitamins relevant to energy metabolism in muscle, and oxidative stress markers. Omega-3 index on the fatty acids add-on quantifies EPA and DHA directly. Together these give a comprehensive biochemical picture of the musculoskeletal environment that no imaging study provides.
Know the biochemistry behind your structural health
Vitamin D, magnesium, omega-3 index, vitamin C, inflammatory markers, and creatine kinase — the functional blood picture that tells you whether your tissue has the substrates to repair and the biochemical environment to heal.
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