16.1 Paediatric Musculoskeletal Development

Quick Answer: Children are not small adults—open growth plates, evolving alignment, and developmental stage change risk and loading rules. Escalate fever + non-weight-bearing limp, night/systemic pain, and possible SCFE (adolescent knee pain + limited hip IR). Manage youth overuse with load–capacity modification, not forced full rest forever or play-through. Partner with carers, seek assent, and route DDH/CTEV to orthopaedic pathways early.

Paediatric musculoskeletal (MSK) practice appears in the APC Written Assessment as lifespan-embedded musculoskeletal reasoning rather than a stand-alone “paeds paper.” Vignettes may involve infants with hip concerns, toddlers with limps, school-age children after fractures, or adolescents with overuse injuries from sport. The safe entry-level response combines growth biology, developmental context, red-flag screening, and family-centred communication. You are not expected to replace a paediatric orthopaedic surgeon. You are expected to recognise when a child’s presentation is ordinary for age, when load management and education are appropriate, and when urgent medical review is required.

Growth Plates, Alignment, and Why Children Are Not Small Adults

The immature skeleton differs from the adult skeleton in ways that change both risk and management. Physeal (growth plate) cartilage is relatively weaker than surrounding ligaments and bone. In adults, a twisting injury may sprain a ligament; in a growing child, the same force may produce a physeal injury that can affect future growth if missed or mismanaged. Entry-level physiotherapy does not grade Salter–Harris fractures on X-ray independently, but APC-style reasoning expects you to:

• Treat significant post-trauma pain, swelling, deformity, or inability to weight-bear as medical/imaging priorities, not “just a sprain until proven otherwise.”
• Avoid high-force joint mobilisation or aggressive stretching across an acutely injured growth region without a clear diagnosis and clearance.
• Understand that referred pain patterns and incomplete history from a young child raise uncertainty—default to safety and liaison.

Normal developmental alignment also evolves. Infants and toddlers commonly show physiological genu varum that gradually shifts toward valgus in early childhood, then trends toward more neutral alignment later. Flat feet in young children are often flexible and part of normal development. The exam trap is pathologising normal age-related posture or dismissing progressive, asymmetric, painful, or function-limiting alignment changes as “just growing pains.” Growing pains, when used as a label, should not explain unilateral limp, night pain that wakes the child consistently with systemic features, or progressive functional loss.

Bone mineral accrual, muscle–tendon unit length relative to bone growth, and neuromuscular control all change through adolescence. Rapid growth periods can temporarily alter coordination and flexibility, contributing to apophyseal and overuse presentations. Load prescription must respect chronological age, biological maturity, training history, and sport demands, not only the calendar age printed on the referral.

Developmental Dysplasia of the Hip (DDH) and Clubfoot Awareness

DDH is a spectrum from mild acetabular dysplasia to frank dislocation. Early detection improves outcomes. Physiotherapists may encounter DDH in neonatal screening contexts, infant motor clinics, or later as gait asymmetry, limited abduction, or leg-length discrepancy. Entry-level expectations include:

• Knowing that risk factors and clinical signs (asymmetric thigh folds, limited hip abduction, Galeazzi sign, abnormal Ortolani/Barlow findings in appropriate age windows) warrant prompt orthopaedic/paediatric pathway, not “watch and wait” physiotherapy alone when instability or dislocation is suspected.
• Supporting families with positioning education consistent with medical plans (for example, avoiding extreme swaddling positions that force hips into adduction and extension when this conflicts with hip-healthy positioning advice).
• Understanding that late-presenting DDH may present as limp, Trendelenburg gait, or activity-related pain—asymmetric findings are more concerning than symmetric flexible flat feet.

Clubfoot (congenital talipes equinovarus, CTEV) is typically managed with early orthopaedic pathways (often Ponseti casting and bracing). Physiotherapy’s role at entry level is awareness, functional support, and family education rather than independent primary correction. After formal treatment, children may need monitoring of brace adherence, residual stiffness or weakness, and gait quality. Exam cases often test whether you escalate appropriately and partner with the family rather than improvise aggressive manual “correction” outside scope and protocol.

Both conditions illustrate a broader APC theme: early recognition + correct pathway + collaborative care beats delayed “general strengthening” when structural congenital or developmental orthopaedic conditions are present.

Youth Sports Injuries: Load, Growth, and Return-to-Play Thinking

Adolescent athletes frequently present with:

• Apophyseal conditions (for example, Osgood–Schlatter-type tibial tubercle traction symptoms, Sever’s calcaneal apophysitis) related to repetitive loading during growth.
• Physeal stress injuries and overuse syndromes when training volume spikes.
• Acute soft-tissue injuries and traumatic joint injuries that still require growth-aware precautions.
• Sport-specific patterns (jumping/landing sports and knee/ankle loads; overhead sports and shoulder loads; running sports and lower-limb bone stress risk).

Safe reasoning emphasises load–capacity balance. Capacity is reduced by recent growth spurts, poor recovery, inadequate strength base, prior injury, rapid sport specialisation, and concurrent illness. Load increases when athletes add teams, tournaments, intensives, or return too quickly after time off.

High-value physiotherapy actions include:

1. History that captures training volume, surfaces, footwear, recent growth, pain behaviour, and night pain.
2. Objective assessment of swelling, effusion, joint stability, neurovascular status, limp quality, and functional tests appropriate to age.
3. Activity modification that reduces provocative load while maintaining some fitness and psychosocial participation where safe.
4. Progressive strengthening, neuromuscular control, and graded return criteria rather than calendar-only clearance.
5. Education for athlete and parent/carer about pain that worsens with continued high load, night pain, swelling, mechanical locking, or instability—these change the plan.

Avoid the false dichotomy of “complete rest forever” versus “push through for the team.” Many overuse presentations improve with relative rest, technique and load adjustments, and progressive capacity building. However, inability to weight-bear, deformity, joint locking, neurovascular compromise, or systemic red flags override sports timelines.

Red Flags: Infection, Malignancy, and the Non-Mechanical Limp

A limp in a child is not automatically “MSK minor.” Red-flag features that should trigger urgent medical escalation include:

• Fever, rigors, or unwell appearance with limp or joint refusal
• Night pain that wakes the child, progressive pain at rest, or constant severe pain
• Weight loss, night sweats, unexplained fatigue, or lymphadenopathy concerns
• Refusal to weight-bear or move a joint (especially hip) in a febrile child
• Rapidly progressive neurological signs, bowel/bladder changes (rare but critical), or spinal deformity with systemic illness
• History suggesting non-accidental injury patterns (inconsistent history, delayed presentation, injuries not matching mechanism)—escalate via mandatory local child-protection pathways and medical review

Septic arthritis, osteomyelitis, and other infections can destroy joints rapidly—especially the hip. Malignancy (primary bone tumours, leukaemia-related MSK symptoms) may present with night pain, limp, or systemic features. Transient synovitis can mimic infection but is a medical differential, not a physiotherapy first-line diagnosis to “treat and see.” APC-safe behaviour is: screen, do not dismiss, escalate early, document, and communicate clearly with carers.

After serious pathology is excluded, common paediatric limps may relate to trauma, overuse, developmental hip issues, Legg–Calvé–Perthes disease, slipped capital femoral epiphysis (SCFE) in older children/adolescents (often referred pain to knee—do not ignore hip screening), or biomechanical factors. SCFE is a medical/orthopaedic urgency when suspected (antalgic gait, limited internal rotation, referred knee pain in an adolescent, especially with risk factors). Physiotherapy does not “mobilise through” a possible SCFE.

Parent/Carer Partnership and Consent with Minors

Children and adolescents rarely attend physiotherapy alone as decision-makers in the same way adults do. Entry-level professional practice requires:

• Partnership with parents/carers for history, home program adherence, school/sport negotiation, and safety netting (what to watch for overnight).
• Developmentally appropriate communication with the child: explain what you will do, seek assent for hands-on assessment where possible, and watch for fear or distress.
• Understanding that legal consent frameworks for minors vary by jurisdiction and capacity, but professional standards consistently require respectful information-sharing, privacy considerations (especially with adolescents), and clarity about who decides treatment when capacity is limited.
• Confidentiality nuances with older adolescents: support autonomy while recognising duty-of-care and mandatory reporting obligations for risk of harm.
• Cultural safety: families may have different beliefs about touch, undressing for assessment, gender of therapist, and authority in decision-making—negotiate respectfully and use chaperones where appropriate.

On the APC Written Assessment, the best answer often combines clinical safety with collaborative, family-centred practice. Example: modifying a sports plan with both the adolescent’s goals and the carer’s understanding of load limits; or pausing aggressive treatment when a child is distressed and re-explaining rather than forcing compliance.

Practical Assessment and Intervention Principles

A structured paediatric MSK encounter typically includes:

• Clear reason for attendance and red-flag screen
• Birth/developmental milestones when relevant (especially infants/toddlers)
• Pain behaviour, night symptoms, fever, and systemic review
• Observation of posture, gait, play, and spontaneous movement
• Age-appropriate strength, ROM, and functional tests
• Shared goals that matter to child and family (play, school PE, sport, sleep, comfort)
• Home advice that is simple, supervised, and realistic for family routines

Intervention emphasis is usually active, education-rich, and functionally oriented. Passive techniques may have a role for comfort or specific indications but should not replace progressive movement and load management. Exercise programs must match attention span and motor skill level—games-based and short-bout formats often work better than adult gym templates.

Integrating Paediatric MSK into APC Case Strategy

When a case involves a child:

1. Triage seriousness first (infection/malignancy/fracture/SCFE/non-accidental injury concerns).
2. Interpret findings through growth and development, not adult cut-offs alone.
3. Choose interventions that are safe for open growth plates and developmental stage.
4. Partner with carers and set clear review/escalation criteria.
5. Coordinate with GP, paediatrician, orthopaedics, school, or coach when indicated.

Closing Exam Anchor

Growth plates + evolving alignment = not a small adult; DDH/CTEV = early pathway, not solo fixing; youth sport = load–capacity with relative rest; fever/night/systemic limp = escalate; minors = assent + carer partnership + safeguarding awareness.