Muscle spasm is a common problem in rehabilitation and sports medicine. It refers to an involuntary contraction of muscle fibres, which may be short-lived or sustained. Clinically, muscle spasm is often associated with pain, stiffness, fatigue, reduced movement, and impaired function.

Massage therapy is commonly used to reduce muscle tension, improve comfort, and support recovery. However, the biological mechanisms behind its effects are still being investigated. A study from China explored whether massage may help muscle spasm not only by relaxing tissue mechanically, but also by improving muscle metabolism.

What Did the Study Do?

The researchers used a rat model of gastrocnemius muscle spasm caused by treadmill-induced fatigue. The animals were divided into control, spasm model, and massage groups.

The massage group received a kneading intervention once daily for 7 days. The treatment was applied to the BL57 point, using a controlled force and frequency.

The researchers then measured pain sensitivity, muscle tone, blood flow properties, fatigue-related blood markers, muscle structure, and muscle metabolites.

Main Findings

Massage produced several beneficial effects.

First, it increased pain thresholds. Rats with muscle spasm became more sensitive to mechanical and heat stimulation. After massage, their sensitivity decreased, suggesting a pain-relieving effect.

Second, massage reduced muscle tone. The spasm group showed higher resting muscle stiffness or internal pressure. After massage, muscle tone decreased toward normal levels.

Third, massage improved blood flow properties. Muscle spasm was associated with thicker, more viscous blood, which may slow circulation and reduce metabolite clearance. Massage reduced blood viscosity, suggesting improved microcirculation.

Fourth, massage reduced fatigue-related markers. Lactic acid and blood urea nitrogen were elevated in the spasm group. These markers are linked to anaerobic metabolism, fatigue, and protein breakdown. Massage lowered both markers.

Fifth, massage improved muscle structure. Under electron microscopy, spasmed muscle showed disorganised muscle fibres, damaged Z-lines, and fewer mitochondria. After massage, muscle fibres appeared more orderly, and mitochondria were more visible.

Why Metabolism Matters in Muscle Spasm

Muscle relaxation requires energy. When a muscle remains contracted for too long, blood flow may be restricted. This can reduce oxygen delivery and slow the removal of metabolic waste products.

One important waste product is lactic acid. When oxygen supply is insufficient, muscle relies more heavily on anaerobic glycolysis, producing more lactic acid. If lactic acid accumulates, the local environment becomes less favourable for normal contraction and relaxation.

The massage group had:

• Lower blood lactate (LA) levels than the untreated muscle spasm group.
• Lower blood urea nitrogen (BUN).
• Lower blood viscosity, suggesting improved microcirculation.
• Improved muscle ultrastructure.
• Changes in metabolic pathways involved in energy metabolism.

Massage appears to improve muscle metabolism and circulation, which is associated with lower lactate levels after muscle spasm.

What Did the Metabolomics Show?

The researchers used metabolomics to examine small molecules inside the gastrocnemius muscle. They found that muscle spasm changed many metabolites, while massage shifted the metabolic profile closer to normal.

Several pathways appeared important:

Energy metabolism
Massage influenced pathways related to glycolysis and energy production. This may help restore ATP availability, which is needed for muscle relaxation.

Calcium regulation
Massage affected inositol-related metabolism, which is linked to calcium signalling. Calcium control is central to muscle contraction and relaxation. Poor calcium handling may contribute to persistent contraction or spasm.

Lipid and membrane metabolism
Massage also affected glycerophospholipid and glycerolipid metabolism. These pathways are important for cell membrane function, inflammation, and energy storage. Improved lipid metabolism may help maintain muscle cell integrity after spasm or fatigue.

Amino acid metabolism
Changes in glycine, serine, threonine, valine, leucine, and isoleucine pathways suggest that massage may also influence protein turnover and recovery from fatigue.

Clinical Caution

This was an animal study, not a human clinical trial. The findings are useful for understanding possible mechanisms, but they do not prove that the same effects occur in exactly the same way in people.

The study also used a specific massage protocol and a specific spasm model. More human research is needed to confirm which massage techniques, doses, and patient groups benefit most.