03/23/2026
Looking at this result caused by minor re-injurys... with a "4 years later" time-gap in-between for the inflammation to fester. These knots or "lactic acid buildup" will effect the surrounding muscle groups that pull around the tension spot in a dysfunctional way, instead of this muscle group just contracting & generating force in unison.
An emphatic response tends to follow pain relief and lets you-as a therpist- know you're on the right track. Overall client will benefit tremendously when you consider their actual trouble spots.
𝗖𝗵𝗿𝗼𝗻𝗶𝗰 𝗖𝗵𝗮𝗻𝗴𝗲𝘀 𝗔𝗳𝘁𝗲𝗿 𝗮 𝗖𝗮𝗹𝗳 𝗠𝘂𝘀𝗰𝗹𝗲 𝗦𝘁𝗿𝗮𝗶𝗻: 𝗔 𝗗𝗲𝗲𝗽 𝗗𝗶𝘃𝗲 𝗶𝗻𝘁𝗼 𝗠𝘂𝘀𝗰𝗹𝗲 𝗔𝗿𝗰𝗵𝗶𝘁𝗲𝗰𝘁𝘂𝗿𝗲 𝗮𝗻𝗱 𝗖𝗼𝗻𝗻𝗲𝗰𝘁𝗶𝘃𝗲 𝗧𝗶𝘀𝘀𝘂𝗲
⬛ Calf muscle strain injuries are incredibly common in sports that involve sudden acceleration and high-speed running, and unfortunately, they are notoriously associated with a high reinjury rate.
⬛ These injuries almost exclusively occur at the delicate interface between the muscle and the aponeurosis, the sheet-like tendinous connective tissue.
⬛ Despite their high prevalence, the long-term structural and functional consequences of gastrocnemius calf strains have received very little attention.
⬛ A 2023 study published in the Scandinavian Journal of Medicine & Science in Sports, titled "Chronic changes in muscle architecture and aponeurosis structure following calf muscle strain injuries," aimed to uncover exactly how the muscle and aponeurosis adapt—or fail to adapt—long after the initial injury.
⬛ Here is a thorough breakdown of the study's methods, key findings, and implications.
𝗪𝗵𝗮𝘁 𝗗𝗶𝗱 𝘁𝗵𝗲 𝗥𝗲𝘀𝗲𝗮𝗿𝗰𝗵𝗲𝗿𝘀 𝗗𝗼?
⬛ The researchers investigated the structural and functional differences between the injured and uninjured calves of 10 participants who had previously suffered a chronic strain in the medial head of the gastrocnemius GM muscle.
⬛ On average, these individuals were 47 months past their initial injury onset.
⬛ Using advanced dynamic and static ultrasound imaging, the researchers measured muscle fascicle length, pennation angle, the angle at which muscle fibers attach to the connective tissue, and the thickness of the deep aponeurosis.
⬛ Measurements were taken at rest in various ankle positions and dynamically while participants performed a unilateral heel-rise exercise.
⬛ Additionally, electromyography EMG was used to assess the neuromuscular activation of the GM and the soleus muscles during the heel rise.
𝗞𝗲𝘆 𝗙𝗶𝗻𝗱𝗶𝗻𝗴𝘀
⬛ The study revealed striking, long-lasting differences between the previously injured calves and the healthy counterparts.
Muscle Fascicle Changes 🧬
⬛ Fascicles are shorter and inactive.
⬛ The muscle fascicles in the most distal portion of the injured GM were significantly shorter than those in the uninjured leg.
⬛ Ultrasound videos showed that the distal fascicles on the injured side rolled inward and took on a pronounced curvilinear shape during muscle contraction, rather than pulling taut.
⬛ The researchers hypothesize that these curved fascicles are essentially inactive and are simply being pulled by the aponeurosis instead of actively contracting and generating force.
Pennation Angle Changes 📐
⬛ While resting pennation angles were similar between sides, the pennation angle of the injured distal GM became significantly steeper during contraction compared to the healthy calf.
Connective Tissue Adaptations 🧵
⬛ The aponeurosis was significantly enlarged thickened in the injured calf compared to the healthy calf, both at rest and during muscle contraction.
⬛ On the healthy side, parts of the aponeurosis naturally thinned during contraction as it stretched.
⬛ The injured aponeurosis actually thickened further during contraction.
⬛ This indicates substantial and long-lasting involvement of the connective tissue during the repair process.
Altered Muscle Activation 🧠
⬛ EMG data revealed that the neuromuscular activation pattern was changed.
⬛ The injured calf displayed significantly higher relative soleus muscle activity compared to the GM during the heel rise.
⬛ This suggests a compensatory or protective strategy where the body relies more heavily on the soleus to perform the movement.
⬛ This may occur due to reduced motor unit recruitment in the injured GM.
𝗪𝗵𝘆 𝗗𝗼𝗲𝘀 𝗧𝗵𝗶𝘀 𝗠𝗮𝘁𝘁𝗲𝗿?
⬛ The results of this study suggest that a calf muscle strain causes long-term, and likely permanent, changes to both the muscle architecture and the neuromuscular system.
⬛ If the muscle fascicles at the distal GM do not actively contract during voluntary movement, the muscle and the aponeurosis are deprived of the essential mechanical tension needed to maintain their strength.
⬛ The researchers propose that this failure to restore a firm, functional connection between the muscle and the connective tissue could be a key reason why calf strains have such a high rate of reinjury.
⬛ These findings encourage a rethinking of current rehabilitation protocols.
⬛ In hamstring injuries, eccentric exercises have been proven to increase fascicle length and reduce reinjury risk.
⬛ However, it is still unknown whether targeted eccentric training for the calf could help lengthen these distal fascicles and restore functional muscle contraction to the injured area.
