Show Notes
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Tendons are frequently discussed as though loading is either therapeutic or harmful. That distinction is too simple. Mechanical loading is essential for tendon homeostasis, adaptation and performance, yet the same load may be tolerated by one athlete and provocative for another. The relevant question is therefore not whether a tendon should be loaded, but whether the magnitude, rate, volume and frequency of loading are appropriate for its present capacity and are followed by sufficient recovery. This distinction is particularly important for the Achilles tendon. During locomotion, the Achilles transmits force from the gastrocnemius–soleus complex and stores and returns elastic energy. Running, jumping, accelerating and changing direction expose it to substantial forces delivered over short time periods.[1,2] Long-term preparation must develop the capacity to tolerate these demands. Acute preparation immediately before activity has a different purpose: it progressively exposes the muscle–tendon unit to force, rehearses relevant movement strategies and provides a practical check of readiness. It cannot produce structural adaptation within minutes, nor should it be presented as an isolated method of preventing injury. Tendon structure, function and adaptation Tendon is a hierarchical, collagen-rich tissue rather than an inert cable. Collagen molecules form fibrils, fibres and fascicles, while the interfascicular matrix permits relative movement between these structures. Tenocytes and tendon-derived cells respond to mechanical deformation through mechanotransduction: mechanical signals are converted into cellular responses influencing collagen synthesis, extracellular-matrix turnover and tendon mechanical properties.[3,4] Adaptation is therefore load-dependent, but it is not determined by external weight alone. Joint position, muscle recruitment, moment arm, contraction type, movement velocity and individual anatomy all influence the force and strain experienced by the tendon. The Achilles is an energy-storing tendon. Its length and compliance allow energy to be stored during loading and returned during propulsion, enabling the calf complex’s muscle fibres to operate over smaller length changes and at slower shortening velocities.[1] This contributes to economic locomotion and repeated force production. Consequently, Achilles capacity cannot be described by calf strength alone. The athlete not only requires sufficient plantar flexion force but also, sufficient rate of force development, tendon stiffness, elastic energy storage and tolerance of repeated contacts. The foot beneath the Achilles is part of the same energy-storing system and deserves attention in its own right. The foot core model reframes the small intrinsic muscles of the plantar arch as active local stabilisers, comparable to the deep stabilisers of the trunk, yet they are still frequently neglected in lower limb rehabilitation.[20] These muscles do more than hold up a static arch. During locomotion the foot behaves as a spring that stores and returns elastic energy across the stretch-shortening cycle, and the intrinsic muscles actively assist this process. Contraction of muscles such as flexor digitorum brevis facilitates tendon stretch and recoil within the arch, contributing to energy storage and return rather than merely supporting a fixed structure.[21] Their more decisive contribution appears to be in stiffening the forefoot into an effective lever for propulsion. When the intrinsic muscles are experimentally inhibited via a tibial nerve block, the positive, propulsive work generated falls substantially at the foot and, importantly, also at the ankle, even though passive structures continue to support the arch itself.[22] The clinical inference is reasonable, although not yet proven. A foot that cannot adequately stiffen and return energy offers a less effective lever and spring
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It always struck me as bizarre that sports medicine and musculoskeletal specialties deal with pain and dysfunction from head to toe in the human body, yet offer little health literacy or inclusion of the pelvic floor. Traditionally considered taboo and someone else’s remit, men and women with issues affecting the pelvic floor have largely suffered in silence. Thankfully, change is afoot, and healthcare is finally evolving. There is much more awareness, inclusion, and understanding of this unique body area and the role that it plays. For anyone playing catch up, the pelvic floor is a group of muscles spanning the base of the pelvic outlet in layers. While both men and women have a pelvic floor, the pelvic outlet is wider in females than in males and it also contains an extra orifice – the vagina [1]. That’s right, we went there. We said the ‘V’ word. Because just like vulva, or vestibule, the vagina is simply an anatomical term. It needn’t be embarrassing or taboo. Some of you will be long enough in the tooth to remember when the word ‘breast’ was taboo. However, with healthcare campaigns for breast cancer and breastfeeding, this term became an anatomical norm. We need to do the same for the pelvic floor and its related anatomy and physiology. What does the pelvic floor do? In both men and women, the pelvic floor serves to control the bladder and bowel (maintain continence), empty the bladder and bowel (voiding and defecation) and support sexual function (arousal and climax). In women, the pelvic floor also plays an important role in pelvic organ support. Remember that extra orifice I mentioned earlier…well this area is high risk for connective tissue laxity and defects meaning that the pelvic organs (bladder, uterus, rectum) can descend into the vaginal cavity causing symptoms of heaviness, pressure and a sensation of ‘something in the vagina’. What are the signs and symptoms of pelvic floor dysfunction? If the pelvic floor is not doing its job, any of its roles can become compromised. This may manifest in leaking from the bladder or bowel, inability to fully empty the bladder or bowel, pain ‘down there’, sexual dysfunction (compromised erection, dyspareunia, pain with climax) or heaviness and pressure in the vaginal region (for women) [2]. A full list of sex-specific signs and symptoms of pelvic floor dysfunction can be seen in Table 1. Table 1 - signs and symptoms of pelvic floor dysfunction in men and women Who gets pelvic floor dysfunction? Pelvic floor dysfunction can affect any man, woman or child, however it is particularly problematic for women, especially during transitional life events, such as pregnancy/childbirth and the menopause [1]. One in three women will experience pelvic floor dysfunction [3] and for those that engage in sport, the prevalence of symptoms varies according to the load demands of the activity. For example 61% of netballers leak urine [4], up to 43% of female rugby players leak [5], and 32% of gymnasts experience incontinence [6]. Structural changes associated with vaginal childbirth and aging, as well as lower levels of oestrogen to lubricate and bulk out the tissues can increase the odds of experiencing pelvic floor dysfunction. However, even young adolescent females can leak urine due to the load demands of their sport. For example, in athletics and gymnastics, stress urinary incontinence (the involuntary leakage of urine during activities involving high levels of intra-abdominal pressure) is commonly experienced. Yet no-one is doing anything about it. No one is screening. No one is signposting. No one is educating these younger athletes that pelvic floor symptoms are not to be expected and normalised. Or that they simply indicate that the sporting demands exceed the load capacity at the pelvic floor. If this was any other area of sports or MSK practice, would we settle for a load capacity that does not meet the demands of the sport?! Why is this relevant to every therapist, no matter their di
This is a free preview of a paid episode. To hear more, visit mskmag.substack.com
This is a free preview of a paid episode. To hear more, visit mskmag.substack.com
This is a free preview of a paid episode. To hear more, visit mskmag.substack.com
This is a free preview of a paid episode. To hear more, visit mskmag.substack.com