{"id":11518,"date":"2025-03-21T15:51:19","date_gmt":"2025-03-21T14:51:19","guid":{"rendered":"https:\/\/blogs.bmj.com\/bjsm\/?p=11518"},"modified":"2025-03-21T15:51:19","modified_gmt":"2025-03-21T14:51:19","slug":"an-additional-response-the-nervy-business-of-t-junction-hamstring-injuries","status":"publish","type":"post","link":"https:\/\/blogs.bmj.com\/bjsm\/2025\/03\/21\/an-additional-response-the-nervy-business-of-t-junction-hamstring-injuries\/","title":{"rendered":"An additional response: The \u2018nervy\u2019 business of T-junction hamstring injuries"},"content":{"rendered":"

This blog provides further considerations regarding the neurological influence on distal musculotendinous junction injuries of the biceps femoris.<\/span><\/p><\/blockquote>\n

Introduction<\/h4>\n

Previous BJSM blogs (<\/span>a<\/span><\/a> and <\/span>b<\/span><\/a>)<\/span> explored posterior thigh stretch combined with trunk flexion\/rotation, with neural involvement, as a potential mechanism of injury for biceps femoris T-junction. This post further considers the neural components within our rehabilitation.\u00a0<\/span><\/p>\n

1) The nerves\u2019 mobility:<\/h4>\n

91% of hamstring experts agree that \u201cneural mobility could be considered\u201d in treatment of hamstring injuries but that \u201cthe protection of the repaired or vulnerable tissue should be maintained\u201d (1). Introducing torso and spine challenges during our hamstring exercises seems a very reasonable idea, with consideration of factors such as foraminal compromise, disc stress or lumbar instability to ensure we are protecting the nerves near their root. A skilled assessment of lumbopelvic mobility, stability and control might give us more confidence. More widely, such an assessment allows us to identify other lumbopelvic influences on hamstring injuries such as force closure, anterior pelvic tilt and pelvic asymmetry and address these as part of a comprehensive rehabilitation strategy (1).\u00a0<\/span><\/p>\n

2) Neuromuscular control and inhibition;<\/h4>\n

If the T-junction is a more complex neurological area, plus we\u2019re seeing longer hamstring recovery times and\/or higher re-injury rates, we might also consider the neurological process required to achieve an appropriate hamstring contraction.<\/span><\/p>\n

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Figure 1: Considering the entire neurological process. Is it a software issue as well as a<\/span> hardware issue? Picture taken from Haggie et al., 2023\u00a0<\/span><\/em><\/p>\n

Prolonged weakness (3) or eccentric-specific weakness (4, 5) may be signs of neurological inhibition. However, hamstring experts are yet to agree on whether inhibition plays a role in hamstring injuries (1). If it is considered, it might only be at the end of a rehabilitation process when we see chronic weakness despite adequate loading, or reinjury despite good tissue healing.<\/span><\/p>\n

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Figure 2: Neuromuscular inhibition is difficult to test for in a lab setting, let alone a clinical setting. But what clues might lead us to suspect it? Might it be an earlier consideration with T-junction injuries?\u00a0<\/span><\/em><\/p>\n

Concentric exercises do not appear to restore neuromuscular function, it is the eccentric component of strength exercises that appears to act as the stimulus for change (6). Lifting heavy is likely to increase neural drive which might also be a stimulus for neurological adaptation (7). However, our standard hamstring strength programmes routinely involve these elements anyway.\u00a0<\/span><\/p>\n

The below ideas should clearly not form the focus of hamstring rehab, but may be considered as creative adjuncts if we are suspecting neuromuscular inhibition. Might using them immediately before\/during a strength session help an inhibited hamstring adapt to the subsequent training stimulus?\u00a0<\/span><\/p>\n

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Figure 3: When one muscle has higher tone, its antagonist may be inhibited, termed reciprocal inhibition (8). With the biceps femoris, does its antagonists (hip flexors or knee extensors) have increased tone and can we reduce this?\u00a0<\/span><\/em><\/p>\n

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Figure 4: Spinal Manipulation may affect sensorimotor integration at the level of the brain. It may also result in strength changes into the lower limb lasting 30-60 minutes. Might manipulation have a positive downstream influence on the hamstring? (9,10,11)<\/span><\/em><\/p>\n

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Figure 5: An external pelvic compression belt has been shown to increase eccentric hamstring strength in terminal range between 5-10% on isokinetic testing (12,13) Longer-term, we might re-create some of the effect of this belt through progressive lumbopelvic strength\/stability exercises that improve the force closure. (Picture taken from Arumugam et al., 2015).\u00a0<\/span><\/em><\/p>\n

Conclusion<\/span><\/h4>\n