• A vertebral fracture (that isn’t healed).
• 
  
• Severe scoliosis (Cobb angle > 45°).
• 
  
• A malignant, spinal tumour.
• 
  
• A spinal infection (e.g. meningitis).
• 
  

Note: In medical terms, these conditions are referred to as contra-indications.

Cautionary Advice

In addition to this, the following advice should be noted:

• You should not use the rack if you’re pregnant (beyond 6 months).
• 
  
  
• The elderly or infirm may find it difficult to use – this is due to the fact that most of the exercises are performed on the floor.

Height Restrictions

The following height restrictions should also be observed:

• The small backrack is suitable for anyone between
• 
  1.55m and 1.75m tall (5' 1" to 5' 9").
  
  
• The large backrack is suitable for anyone between
• 
  1.75m and 2.00m tall (5' 9" to 6' 6").