Educational draft · awaiting clinical reviewThe full textbook explains uncertainty but does not replace live national or local guidance, specialist advice, or current prescribing information.
Weight-bearing status and mobilisation
Musculoskeletal medicine and orthopaedics · UK scope · Sources checked 27 Aug 2026 · Clinical review pending
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Stop mobilisation when limb safety changes
New deformity, a wound problem, sudden mechanical pain, neurovascular change, escalating compartment-type pain, syncope or cardiopulmonary instability makes the existing mobilisation prescription unsafe.
Action: Stop loading, support the patient, use ABCDE where appropriate, repeat wound and distal neurovascular examination and obtain urgent senior orthopaedic or medical review before further mobilisation.
Purpose and principles
Translate fracture or fixation stability into precise limb-specific loading and mobilisation instructions that patients and every rehabilitation professional can apply, review and safely progress.
A loading prescription converts mechanical knowledge into daily behaviour. The surgeon considers fracture geometry, reduction, fixation stability, bone quality, cartilage or tendon repair and soft-tissue protection. The physiotherapist and occupational therapist test whether the patient can follow that prescription during bed mobility, transfers, toileting, stairs and realistic distances. Nurses reinforce safe practice, while the patient and carers need language that works at home. A technically correct restriction that cannot be performed is not a complete rehabilitation plan.
Assign a status separately to each affected limb using the BOASt terms. Non Weightbearing means the plan permits no limb loading during the defined activities. Limited Weightbearing must be described through practical activity or distance, not a percentage or target force that cannot be reproduced reliably. Unrestricted Weightbearing removes a load limit but does not guarantee normal gait, balance or independence. Record required crutches, frame, brace settings, transfer technique, supervision and restrictions on stairs, sport, driving or work.
Indications, selection and cautions
Mechanically achievable plan
The patient can transfer and walk the permitted distance with the named aid while maintaining the intended limb restriction.
Ambiguous loading language
Terms such as partial or touch weight bearing leave patients and teams unable to reproduce one consistent instruction.
Restriction-related harm
New weakness, pressure damage, chest decline, constipation or dependence can result when protection is not paired with active rehabilitation.
Construct warning change
A sudden pain increase, deformity, shortening, wound change or functional loss after loading suggests mechanical or infectious complication.
Medical barrier to mobilisation
Postural symptoms, hypoxia, delirium, anaemia, hypoglycaemia or oversedation may be the limiting factor rather than the operated limb.
Home-task mismatch
A patient safe for ten metres on a level ward may still be unable to manage stairs, a low toilet or essential kitchen tasks.
Red flags requiring action
Pain that becomes severe or disproportionate during mobilisation, particularly with pain on passive stretch, requires urgent assessment for compartment syndrome or fixation failure.
A cool pale limb, absent pulse, delayed capillary refill, new motor loss or progressive numbness after surgery needs immediate neurovascular reassessment and escalation.
Assessment before treatment
01First-line bedside mobility assessmentFirst stepFirst line
Why
Test transfers, gait, aid use, balance, symptoms and adherence to the exact loading prescription.
Interpretation and limitations
Document assistance and distance; inability to comply triggers plan review rather than unsupervised repetition.
02Repeat wound and distal neurovascular examination
Why
Detect perfusion, nerve, compartment, swelling or wound changes before and after mobilisation.
Interpretation and limitations
Any deterioration from baseline requires loading to stop and urgent orthopaedic assessment.
03Orthostatic observations and focused medical review
Why
Identify hypotension, arrhythmia, hypoxia, anaemia, medication effect or metabolic barriers to safe standing.
Interpretation and limitations
Treat reversible physiology and reassess; permitted limb load does not override an unsafe whole-patient response.
04Follow-up radiographs when clinically scheduled or symptoms change
Why
Assess alignment, healing, implant position and whether mechanical criteria for progression are met.
Interpretation and limitations
Radiographic findings must be integrated with construct type and examination; time alone does not prove readiness.
Treatment approach
01PrescriptionWrite a usable loading planFirst stepSurgery, fracture treatment or musculoskeletal injury changes safe limb loading.+
1Assign Non, Limited or Unrestricted Weightbearing separately to every affected limb.
2For Non or Limited status, document clinical justification, functional or distance limit, duration and planned progression phases.
3Record walking aids, brace settings, range restrictions, supervision and relevant tasks such as stairs or transfers.
4Copy the same instruction into operative, nursing, therapy, patient and discharge documents.
02First mobilisationTest safety and feasibilityThe patient is medically ready to sit, stand or walk after injury or surgery.+
1Check observations, cognition, analgesia, wound and distal neurovascular baseline before movement.
2
Complications, monitoring and follow-up
Record permitted status for each limb and check that all clinical documents display the same current instruction.
Measure transfer assistance, walking aid, distance, gait quality, symptoms and adherence at each therapy contact.
Inspect wound, swelling, pressure areas and distal neurovascular status after meaningful changes in activity.
Review pain control, sedation, bowel function, hydration and orthostatic symptoms that can impede safe mobility.
Reassess inpatient status within seventy-two hours, or within twenty-four hours if it directly prevents discharge.
At each follow-up, document whether criteria are met to continue, relax or reimpose restrictions and who has been informed.
Special situations
Loading and mobilisation differ
A limb may have unrestricted loading while the person still needs help because balance, cognition or endurance remains poor.
Percentages are not reproducible
Patients cannot reliably deliver a prescribed fraction of body weight, so BOASt favours concrete activities and distances.
Upper limbs determine feasibility
Crutches demand grip, shoulder strength and coordination; arthritis or neurological impairment can make a lower-limb restriction impossible.
Protection has physiological cost
Every unnecessary day of restriction can accelerate sarcopenia, dependency, thrombosis, pressure injury and fear of movement.
Unrestricted is not unassisted
Removing a mechanical load ceiling does not remove the need for a frame, supervision, pacing or falls precautions.
Common pitfalls
01
Writing partial weight bearing without a practical distance, task, duration or aid.
02
Assuming every patient can use crutches without testing upper-limb strength and cognition.
03
Allowing conflicting weight-bearing instructions to persist across notes and discharge documents.
04
Progressing solely because a set number of weeks has passed without reviewing symptoms, healing and construct stability.
05
Using pain alone to permit loading when neuropathy or analgesia can mask mechanical danger.
06
Delaying discharge for a restriction without triggering the required prompt clinical review.
Practice
Two practice questions
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Question 1 of 2
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Musculoskeletal medicine and orthopaedicsOriginal SBA
BOASt loading terminology
An operation note says the patient should perform twenty-five percent partial weight bearing for six weeks. Which rewrite best follows current BOASt terminology?
Sources and review status4 sources · checked 27 Aug 2026 · clinical review pending+
Sources
Sources and review status
National guidance is shown before implementation-dependent detail. Apply principles in context and verify current guidance when a decision affects care. Source check completed 27 Aug 2026; clinical approval remains outstanding.
Before first mobilisation, inspect dressings and swelling, document distal perfusion, motor and sensation and check pain control without excessive sedation. Assess cognition, delirium, hearing, vision, pre-injury mobility, upper-limb capacity to use aids, the opposite limb and orthostatic symptoms. Trial the safest aid under supervision. Record distance, assistance, symptoms, gait quality and whether the intended loading was achievable. Failure may reflect weakness, fear, pain, neurological disease or ambiguous instructions rather than unwillingness.
Rehabilitation progression is condition specific. A stable arthroplasty or robust fixation may permit unrestricted early loading, while an articular reconstruction, tendon repair, unstable fracture or tenuous fixation may require temporary limitation. Protection has costs: muscle loss, stiffness, pressure injury, VTE, chest complications and loss of independence. Conversely, premature excess load may displace a fracture, stretch a repair or break fixation. The plan therefore needs a defined balance, review interval and criteria for changing phases.
Communicate the same wording across operation note, ward board, therapy record, discharge letter and patient information. If different entries conflict, stop and obtain clarification from the responsible orthopaedic team. Provide pictures, demonstration or translated material where helpful, and ask the patient to show the technique back. At every review, reconcile symptoms and radiographs with functional progress. A discharge blocked solely by weight-bearing status warrants review within twenty-four hours under BOASt, including whether the restriction remains necessary or the support package can change.
Key points
Weight-bearing status describes permitted load through each affected limb; mobilisation describes how the person transfers, stands, walks and uses aids within that permission.
BOASt recommends only three terms: Non Weightbearing, Limited Weightbearing and Unrestricted Weightbearing; abandon touch, partial, proportional, permissive and progressive weightbearing labels.
For Non or Limited Weightbearing, document the clinical reason, functional or distance restriction, duration, planned phases, walking aids and any brace or rehabilitation protocol.
Do not quantify Limited Weightbearing as a percentage of body weight or kilograms of force; specify practical boundaries such as transfers only, indoor distance or no stairs.
First mobilisation assessment checks observations, pain, cognition, orthostatic symptoms, wound, distal neurovascular status, strength, balance, home demands and ability to use the prescribed aid.
Review inpatient status no later than every 72 hours, within 24 hours when it directly prevents discharge, and at every follow-up point.
Early mobilisation is usually desirable after hip fracture and joint surgery when medically and surgically safe, but it must follow the exact fixation, soft-tissue and loading plan.
Progression needs explicit criteria and ownership; the absence of a new instruction is not permission for patients or community teams to guess.
A new wound leak, expanding swelling, visible deformity or a sudden crack with loss of function requires loading to stop until the construct is reviewed.
Chest pain, syncope, unexplained tachycardia or hypoxia during therapy may represent PE, myocardial ischaemia or another acute medical event.
Dizziness with a blood-pressure fall, hypoglycaemia, oversedation or delirium can turn otherwise permitted weight bearing into an immediate falls risk.
A patient unable to understand or physically achieve restricted loading needs a revised construct, brace, aid or supervision plan rather than repeated blame for non-adherence.
05Occupational home-function assessment
Why
Determine whether restrictions can be performed during stairs, toileting, washing, meal preparation and access.
Interpretation and limitations
Equipment, technique, care or temporary alternative accommodation may convert an unsafe discharge into a feasible plan.
Select and fit the aid, teach the technique and supervise transfers before increasing distance.
3Record symptoms, assistance, distance, gait and whether the loading restriction was actually maintained.
4EscalationEscalate medical instability, limb warning changes or an unachievable plan before further attempts.
03ReviewProgress by criteriaTime, healing, symptoms or discharge needs prompt reconsideration of status.+
1Review inpatients at least every seventy-two hours and within twenty-four hours when status directly blocks discharge.
2Integrate examination, wound, radiographs, fixation or tissue-healing constraints and therapy performance.
3Change the status only through a documented responsible-clinician decision with new functional limits and duration.
4Recheck the prescription at every follow-up and communicate progression to community teams and the patient.
04Unexpected deteriorationProtect before reloadingPain, deformity, wound, neurovascular or systemic status worsens during rehabilitation.+
1Stop mobilisation, support the limb and use ABCDE if the patient is systemically unwell.
2Repeat focused limb and medical assessment and identify the last safe functional baseline.
3Obtain urgent imaging or specialist review according to the suspected mechanical, vascular, neurological or medical problem.
4Issue a replacement loading instruction only after the new risk has been defined.