Government reforms aiming to protect mental health patients from unsafe restraint recently came into force following the death of 23-year-old Olaseni Lewis after he was restrained by police officers in London.
NHS Digital figures show restrictive interventions were used roughly 15 times on Burnley patients with learning disabilities, autism or in secondary mental health services in 2020-21.
This was up from around five interventions in 2019-20.
Of those last year, up to four instances saw patients put in the prone position, where they are physically pinned face-down against the floor or another surface – a practice which is said to carry a serious risk of death.
Figures below five are suppressed to prevent identification of individual patients.
Across England, 151,554 restrictive interventions were used last year – more than two-thirds of which were forms of physical restraint.
This was a 15% rise from the 131,338 interventions the year before, and almost double the 80,387 recorded in 2016-17 – the first year of figures available.
Of those last year, 12,420 were prone restraints – also the highest number on record.
Restrictive interventions include forms of physical, mechanical and chemical restraint, as well as seclusion and segregation.
New guidance was introduced in early December in memory of Mr Lewis, who died in September 2010 days after he fell unconscious while being restrained by 11 police officers at a London hospital.
The Mental Health Units (Use of Force) Act 2018 aims to ensure the use of force against patients in mental health units is better governed and requires police to wear body cameras while carrying out restraint, unless there are legitimate operational reasons for not doing so.
Mental health charity Mind hopes this signifies an end to the use of force and a "radical reduction of restraint" on patients.
Alison Cobb, senior policy advisor at Mind, said: "The huge number of restrictive interventions shows how pervasive the use of force is as a part of mental health culture.
"It represents daily traumatisation of people in hospital for mental health care and underlines how crucial implementation of Seni’s Law is."
Though the guidance is a "good basis", she said fully funded reform of the Mental Health Act and improved staffing levels are needed to make wards safer.
The figures show black people across England were almost five times as likely to face restrictive interventions as white people.
In 2020-21, the equivalent of 95 black patients per 100,000 were subject to the measures, compared to just 21 per 100,000 white people.
Rethink Mental Illness also welcomed the Seni's Law reforms but said it is "highly concerning" to see a rise in the number of restrictive interventions.
Alexa Knight, associate director for policy and practice at the charity, added: "While mental health services have been under pressure due to the pandemic, it is unacceptable that there has been no progress to address the stark inequalities in the racialised use of restraint."
A Department of Health and Social Care spokesman said Seni’s Law will reduce the use of inappropriate force in mental health settings.
He added: “We are clear restrictive interventions or restraint should only ever be used proportionately and as a last resort."