1.6 Describe external factors, including shearing forces, which may exacerbate risk of impaired tissue viability and skin breakdown

This guide will help you answer 1.6 Describe external factors, including shearing forces, which may exacerbate risk of impaired tissue viability and skin breakdown.

Tissue viability refers to the health of the skin and underlying tissues. If circulation is poor, or there’s too much pressure or damage, tissue can become unhealthy and break down. This process can lead to pressure ulcers, wounds, and infections. Skin breakdown causes pain, distress, and serious health problems, especially for people who are frail or have limited mobility.

Maintaining healthy skin is important for everyone. People who need regular care are especially at risk. Understanding the external factors which increase the risk of impaired tissue viability is an essential part of care work. This guide covers those factors, focusing on shearing forces and other risks from the environment.

Shearing Forces: Definition and Impact

Shearing happens when the skin remains in the same place but the underlying bone or tissue moves. This often occurs when a person slides down a bed or chair. The skin sticks to the bedding or chair cover, but their bones and tissues shift. This can damage blood vessels and tissues under the skin.

Shear is different to direct pressure. With pressure, the force comes straight down onto the skin. With shear, the force is at an angle, causing layers of tissue to slide over each other.

Shearing causes harm by:

• Stretching and tearing blood vessels
• Reducing blood supply to tissues
• Preventing oxygen and nutrients reaching the tissue
• Increasing the risk of sores and ulcers

Common situations where shear occurs:

• When elevating the head of a bed, and a person slides down
• When transferring a person incorrectly from one surface to another
• When dragging rather than lifting a person

To reduce shearing:

• Use slide sheets and transfer aids
• Keep the person’s posture stable
• Avoid dragging movements
• Ensure the bed or chair is adjusted correctly

Friction and Its Effects

Friction is another key external factor. It is the resistance when the skin rubs against a surface. Friction can strip away the top layer of skin, leaving it red and sore. When combined with moisture or shear, friction increases the risk of skin breakdown.

Examples include:

• Repeated rubbing from bedding or dressings
• Rough handling when moving someone
• Ill-fitting clothing or footwear

Friction can create open areas called friction burns. These are particularly slow to heal and can become infected.

To reduce friction:

• Use gentle handling techniques
• Protect vulnerable areas with soft dressings
• Keep bedding smooth and wrinkle-free

Pressure as an External Factor

Pressure damage happens when an area of skin is under constant weight, cutting off blood supply. Skin and underlying tissue need a regular flow of blood. Without it, cells die and sores develop.

High-risk areas for pressure damage:

• Heels
• Coccyx (base of the spine)
• Hips
• Elbows
• Shoulder blades
• Back of the head

People who cannot move easily are most at risk. The longer the pressure on one spot, the higher the danger.

How to lower pressure risks:

• Change the person’s position regularly
• Use specialist pressure-relieving mattresses or cushions
• Check high-risk areas often for redness or signs of breakdown

Moisture and Skin Health

Moisture acts as another external threat. Persistent dampness softens the protective outer layer of the skin (maceration). Moisture can come from perspiration (sweat), wound fluid, or incontinence. When the skin is damp, it rubs and damages more easily.

Risks from moisture:

• Incontinence leads to wetness and exposure to chemicals in urine or faeces. This weakens skin and quickens breakdown.
• Sweat, especially in skin folds or under dressings, can also lead to damage.

To manage moisture:

• Change wet clothing, pads, or bedding quickly
• Use barrier creams to protect vulnerable areas
• Check and keep skin dry, especially in creases and hidden places

Temperature and Environment

Skin health is less likely to be protected in poor environments. Overheated rooms, high humidity, or cold, damp settings all increase the risk.

Hot environments:

• Sweat increases, softening and weakening the skin
• Heat worsens the effects of friction and moisture
• Tissues are more likely to become damaged

Cold environments:

• Reduced blood flow slows healing
• Skin may become dry and cracked
• People may lie still and move less, causing more pressure on one area

To create a healthy environment:

• Keep room temperatures comfortable
• Balance humidity levels
• Avoid direct heat or cold on the skin
• Encourage movement if possible

Poor Nutrition and Hydration

Nutrition and hydration are slightly less direct but remain part of the wider environment. Dehydrated skin is fragile and cracks more easily. Without enough protein, vitamins, and minerals, skin struggles to repair itself.

Warning signs of poor nutrition or hydration:

• Dry, flaky skin
• Loss of elasticity
• Slow healing
• Weight loss

Support for nutrition and hydration:

• Offer regular drinks and encourage fluid intake
• Provide a balanced diet, with protein, vitamins and minerals
• Check for swallowing issues or reduced appetite

Equipment, Surfaces and Clothing

External factors include objects and surfaces that come into contact with skin.

Equipment risks:

• Tubes, catheters, and oxygen masks can press against the skin
• Wheelchairs, beds, chairs, and mobility aids may cause pressure or friction if not fitted properly
• Hard, rough, or wrinkled bedding increases the risk of damage

Clothing risks:

• Tight or rough clothing causes friction and pressure
• Seams and fasteners can dig into the skin
• Shoes that do not fit cause sores and blisters

To help:

• Check and adjust equipment frequently
• Use padding if items must rest against the skin
• Dress people in soft, well-fitting clothes and shoes

Sensory Loss and Movement

People who cannot feel discomfort or pain are less likely to notice and move away from pressure or harm. Conditions like diabetes, spinal injuries or stroke affect sensation.

Risks linked to sensory loss:

• Not noticing if skin is being damaged
• Not shifting position when needed
• Not seeing or feeling friction, shear, or excess moisture

To support those with sensory loss:

• Carry out regular checks of skin, especially areas under pressure
• Move people at regular intervals
• Teach people and support staff about signs to look for

External Factors Contributing to Skin Breakdown

Here’s a quick reference table outlining the key external factors and what they cause:

Factor	Description	How it Increases Risk
Shearing Forces	Skin stays still, tissue slides underneath	Tears blood vessels and tissues
Friction	Skin rubs against another surface	Strips top skin layer, creates wounds
Pressure	Sustained force on one spot	Cuts off blood, damages tissue
Moisture	Skin exposed to wetness	Maceration, weakens skin barrier
Temperature	High or low room temperature, drafts	Impairs blood flow or damages skin
Equipment/Surfaces	Hard or uneven surfaces, tubes, poorly fitting aids	Adds pressure, causes sores or ulcers
Clothing	Tight or rough clothing, poor fit	Adds rubbing or pressure
Nutrition/Hydration	Inadequate food or fluids	Skin is less able to heal or resist damage
Sensory Loss	Can’t feel pain or pressure	More likely to stay in dangerous positions

Importance of Observation and Reporting

Being alert to these external factors lets you act before any harm occurs. Early signs of skin at risk include redness, heat, hard tissue, soreness, purple or blistered skin. Report anything unusual to your senior straight away.

Document your findings and interventions each time you check the skin or move the person. Communication helps flags are raised early, and action taken to prevent further harm.

Supporting Service Users at Greater Risk

Some people face extra danger with tissue viability. This includes people who:

• Are bedbound or sit in a chair for long periods
• Cannot move themselves
• Are incontinent
• Have poor nutrition or hydration
• Suffer from conditions affecting sensation, such as diabetes or spinal cord injuries
• Are elderly and have thinner, weaker skin

Tailor your care to increase protection:

• Use specialist equipment on care plans for high-risk people
• Teach people and families about signs to watch for
• Listen if the person says they feel sore or uncomfortable

Best Practice for Reducing Risk

Simple steps make a huge difference.

• Position changes: Reposition people at risk every 2 hours in bed, and at least every hour in a chair. Document these turns.
• Pressure-relieving devices: Use mattresses, overlays, cushions.
• Regular skin inspections: Especially for those who cannot check themselves.
• Keep skin dry: Address incontinence promptly, and use barrier creams.
• Gentle handling: Avoid dragging or pulling. Use sliding sheets or hoists.
• Well-maintained equipment: Check beds, chairs, and supports for wear and tear.
• Support healthy eating: Encourage small, regular meals and fluids.

Training and Safeguarding

Ongoing staff training is key. All staff must:

• Know how to recognise skin at risk
• Understand safe moving and handling methods
• Use equipment correctly
• Be aware of signs and risks from friction, shear, and pressure

Record all training and keep skills up to date.

Legal Duty and Organisational Policies

Meeting your duty of care is a requirement under UK law. The Health and Social Care Act 2008, and the Care Quality Commission’s standards, expect staff to protect the skin health and dignity of people they support.

Policies will cover:

• Regular risk assessments for skin integrity
• Plans to maintain healthy skin
• Procedures for moving and turning
• Reporting and monitoring skin damage

Follow your organisation’s policy. Raise any concerns if you spot poor practice.

Final Thoughts

External factors have a big effect on skin health and tissue viability. Factors such as shearing forces, friction, pressure, moisture, temperature, poor nutrition, poorly fitting equipment, tight clothing, loss of sensation, and inadequate hydration all increase the risk of tissue breakdown and pressure ulcers.

Staying observant and taking action reduces these risks. Work with your team, communicate effectively, and follow good practice. This makes a huge difference in protecting people and promoting better health and well-being.