Pelvis and Endocrine Glands

Part 4 · The trunk

The pelvic floor, and the glands that regulate the body

Two subjects, one chapter

The pelvic floor is the floor of the abdominal canister, the bottom of the load-transfer chain from spine to legs, and a muscle group that a third of adult women and a growing number of men have a clinical problem with. Pelvic health is now a recognised physiotherapy specialty precisely because these are muscles, and muscles are what we treat. Yet it remains one of the least confidently taught regions in the undergraduate curriculum — largely because of embarrassment rather than difficulty.

The endocrine glands appear in an anatomy course because they are anatomical structures with positions, relations and blood supplies. But for a physiotherapist their relevance is different and specific:

• endocrine disease changes the tissue you are treating. Diabetes stiffens tendons and slows healing
• thyroid disease causes myopathy and frozen shoulder
• corticosteroids destroy bone and rupture tendons
• acromegaly causes carpal tunnel syndrome and arthropathy. You will not diagnose these conditions, but you will meet them constantly, and you must recognise when the tissue in front of you is not behaving the way healthy tissue should

Learning outcomes

• Describe the bony pelvis, the pelvic brim, and the greater and lesser pelvis.
• Describe the sacroiliac joint, its stability mechanisms, and evaluate the evidence on its assessment.
• Describe the pelvic floor muscles in layers, with attachments, nerve supply and function.
• Describe the perineum, its triangles, and the pudendal nerve.
• Describe the pelvic viscera in outline and the mechanisms of continence.
• Explain pelvic organ prolapse, urinary incontinence and pelvic pain, and the evidence for pelvic floor muscle training.
• Name the endocrine glands, their positions, hormones and principal disorders.
• Explain the musculoskeletal manifestations of endocrine disease and their implications for physiotherapy.

Part A · The pelvis and pelvic floor

The bony pelvis

Figure 1 · The bony pelvis, male and female

Figure 2 · Form closure and force closure

Figure 3 · Nutation and counternutation

Formed by the two hip bones, the sacrum and the coccyx, articulating at the two sacroiliac joints and the pubic symphysis.

The pelvic brim (inlet) divides it:

The pelvic brim runs: sacral promontory → arcuate line of the ilium → pecten pubis → pubic crest → symphysis.

Pelvic inlet and outlet dimensions, and the male–female comparison, are covered in Chapter 13. The functional summary: the female pelvis is wider, shallower, with a rounder inlet, a wider subpubic angle (80–85° vs 50–60°) and everted ischial spines — adaptations for parturition that also give a longer abductor moment arm requirement and a larger Q angle.

The sacroiliac joint

Stability comes from two mechanisms:

• Form closure — the wedge shape of the sacrum, the ridged interlocking surfaces, and the fact that body weight drives the sacrum down and forward into a self-locking position. The sacrotuberous and sacrospinous ligaments prevent the sacral apex tilting up.
• Force closure — compression generated by muscles and fascia crossing the joint: the posterior oblique sling (latissimus dorsi + contralateral gluteus maximus via the thoracolumbar fascia), the anterior oblique sling (external oblique + contralateral internal oblique and adductors), the longitudinal sling (erector spinae, sacrotuberous ligament, biceps femoris), and the deep local system (multifidus, transversus abdominis, pelvic floor, diaphragm).

An honest note on SIJ assessment

Individual palpation and motion tests for the sacroiliac joint have poor reliability — inter-rater agreement for positional and motion palpation is consistently at or near chance level. What does perform acceptably is a cluster of pain-provocation tests (thigh thrust, distraction, compression, sacral thrust, Gaenslen’s): three or more positive out of five gives useful sensitivity and specificity against the reference standard of a diagnostic anaesthetic block.

Similarly, the notion of the SIJ being “out of place” and needing to be “put back” is not supported: the available movement is 2–4°, and no manual technique has been shown to produce a measurable, lasting positional change. Manual and exercise therapy for pelvic girdle pain works — but through load management, force closure and neurophysiological mechanisms, not through repositioning.

Pregnancy-related pelvic girdle pain is common (up to 20% of pregnancies) and responds to exercise, load management, and a pelvic belt where indicated — not to rest.

The pelvic floor

Figure 4 · The pelvic floor and the perineum

Figure 5 · The floor as the base of a canister

A funnel-shaped muscular sheet closing the pelvic outlet, supporting the viscera, maintaining continence and forming the floor of the abdominal canister.

The pelvic diaphragm

The levator hiatus (urogenital hiatus) is the anterior midline gap through which the urethra, vagina (in females) and anal canal pass — necessarily a weak point, and the route of prolapse.

The perineum

Diamond-shaped, divided by a line between the ischial tuberosities into:

The perineal body — a fibromuscular node between the vagina/bulb of the penis and the anal canal, into which converge the bulbospongiosus, superficial and deep transverse perineal muscles, external anal sphincter, levator ani and the perineal membrane. It is the central anchor of the pelvic floor, and its disruption in obstetric tearing or episiotomy is a major cause of subsequent prolapse and incontinence.

The pudendal nerve (S2, S3, S4)

“S2, 3, 4 keeps the pelvis off the floor.”

Leaves the pelvis through the greater sciatic foramen below piriformis, hooks around the ischial spine and sacrospinous ligament, and re-enters through the lesser sciatic foramen into the pudendal canal. Branches: inferior rectal, perineal (to the superficial pouch and the external urethral sphincter), and the dorsal nerve of the penis/clitoris.

Clinically:

• it is blocked at the ischial spine
• it is stretched in prolonged second-stage labour and in instrumental delivery, a major cause of postnatal incontinence
• and it is entrapped in pudendal neuralgia, which presents as perineal pain worse on sitting and relieved on standing or sitting on a toilet seat — a presentation that is very frequently misdiagnosed for years

Function and dysfunction

The pelvic floor does five things: 1. Supports the pelvic viscera against gravity and intra-abdominal pressure. 2. Maintains urinary and faecal continence through sphincteric action and the anorectal angle. 3. Contributes to sexual function. 4. Forms the floor of the abdominal canister, co-contracting with the diaphragm and transversus abdominis and rising before an expected rise in IAP (a feedforward response, lost in many people with incontinence). 5. Contributes to lumbopelvic stability via force closure.

Continence mechanisms: urethral closure pressure exceeding bladder pressure, supported by intact urethral support (the “hammock” of the anterior vaginal wall and endopelvic fascia against which the urethra is compressed), the striated external urethral sphincter, the smooth internal sphincter, and the anatomical position of the bladder neck within the abdominal pressure zone.

The evidence for pelvic floor muscle training

Supervised pelvic floor muscle training is first-line treatment for stress and mixed urinary incontinence in women, with Cochrane-level evidence: women are around five to eight times more likely to report cure than with no treatment, and it is recommended as first-line in NICE and international guidelines before surgery or medication.

It is also effective for pelvic organ prolapse symptoms (POPPY trial) and, in men, before and after radical prostatectomy, where it accelerates return of continence.

Key practice points: up to 30–50% of women cannot perform a correct contraction on verbal instruction alone — many bear down instead, which is actively harmful. Assessment of the contraction is therefore essential, and supervised programmes substantially outperform unsupervised leaflets. Training must be progressive and sustained (typically at least 3 months), and it must be integrated with breathing and load management rather than performed as isolated squeezes.

The pelvic viscera, in outline

Part B · The endocrine glands

The glands, their positions and their hormones

Figure 6 · The endocrine glands in place

Endocrine disease as it presents to a physiotherapist

This is the section that earns the glands their place in a physiotherapy anatomy course.

Diabetes mellitus — the one you will meet most

India has one of the largest diabetic populations in the world, and a physiotherapist there will see its musculoskeletal consequences daily.

Exercise remains a cornerstone of diabetes management, improving glycaemic control, insulin sensitivity and cardiovascular risk. The practical cautions are hypoglycaemia (particularly with insulin or sulfonylureas), foot inspection, autonomic and retinal screening, and avoiding heavy Valsalva work in proliferative retinopathy.

Corticosteroids — iatrogenic endocrine disease

Long-term corticosteroid use is one of the most common causes of secondary musculoskeletal pathology a physiotherapist will encounter:

• Osteoporosis — rapid, particularly in the first 6–12 months; fracture risk rises at doses as low as 5 mg prednisolone daily
• Proximal myopathy — type II fibre atrophy, presenting as difficulty rising from a chair
• Avascular necrosis — hip, knee, shoulder
• Tendon rupture and impaired tendon healing
• Thin, fragile skin — caution with tape, and with manual techniques
• Hyperglycaemia and impaired healing

Fluoroquinolone antibiotics deserve mention in the same breath: they carry a recognised risk of tendinopathy and rupture, particularly of the Achilles, greatly amplified by concurrent corticosteroids and by age over 60. A patient with sudden Achilles pain on a recent course of ciprofloxacin or levofloxacin needs the drug reviewed, not a loading programme.

Thyroid disease

Both under- and over-activity cause proximal myopathy, which is a common cause of “deconditioning” that does not respond to training. Hypothyroidism additionally causes carpal tunnel syndrome, adhesive capsulitis, myalgia and slow-relaxing reflexes; hyperthyroidism causes osteoporosis, tremor and exercise intolerance.

The screening implication: a patient with bilateral, symmetrical, proximal weakness and fatigue that does not improve with graded exercise should prompt consideration of a metabolic or endocrine cause and appropriate medical referral — not more exercise.

Osteoporosis and the endocrine system

Bone is an endocrine target organ (Chapter 2). The commonest causes of secondary osteoporosis in a physiotherapy caseload are corticosteroid therapy, hypogonadism (including RED-S in athletes and post-menopausal oestrogen loss), hyperthyroidism, hyperparathyroidism and malabsorption. Recognising them changes both the exercise prescription and the referral decision.

Where students consistently go wrong

• Overstating sacroiliac movement. It is 2–4°; nothing “goes out of place”.
• Relying on SIJ palpation tests. Use a cluster of provocation tests, three or more positive.
• Forgetting puborectalis and the anorectal angle as the mechanism of faecal continence.
• Assuming every pelvic floor problem needs strengthening. An overactive floor needs downtraining.
• Teaching pelvic floor exercises without checking the contraction. Up to half of women do it wrong, and some bear down.
• Forgetting the pudendal nerve’s course around the ischial spine and the presentation of pudendal neuralgia.
• Missing prostatic metastasis as a cause of back pain in an older man.
• Treating diabetic frozen shoulder or tendinopathy on standard timelines. They are longer and more resistant.
• Using heart-rate-based prescription in autonomic neuropathy.
• Missing endocrine proximal myopathy and prescribing more exercise for weakness that has a metabolic cause.

Check yourself

15 questions on this chapter. Tap one to see the answer and the reasoning.

Quick review

Further reading

Chapter 21 of 24 · Human Anatomy · Physiotherapist India End of Part 4 — The trunk. Next: Chapter 22 — Skull, Face and Neck, opening Part 5.

Reviewed by the Physiotherapist India Team. · Human Anatomy contents