May 12, 2023

Proof of Market Report: S-Press Device

Proof of Market Report: S-Press Device


NIHR Devices for Dignity MedTech Co-operative (D4D) were commissioned by JT Rehab, Sheffield to undertake independent proof of market research in Sheffield to inform the following Proof of Market report.

Work undertaken by D4D to inform this independent Proof of Market report has included:

  • Review of relevant published evidence on the prevalence, health and economic impact of frailty and deconditioning and current exercise provision
  • Identification of information on existing competitive devices and market opportunity for S-Press
  • Design, distribution and evaluation of an electronic questionnaire for qualified physiotherapists to gain feedback on acceptability, usability, perceived benefits, willingness to pay, to raise awareness, and to establish a base of potential clinical champions
  • A series of face-to-face interviews with Intermediate Care and Nursing Home managers and staff
  • Face-to-face interviews with qualified physiotherapists and care home staff to validate the unmet need and to gain feedback on acceptability, usability, perceived benefits and opportunities for adoption
  • Scoping of interest in trialling and/or adoption of this device

Frailty in the elderly

Increasing average life expectancy is well acknowledged: the United Nations Department of Economic and Social Affairs (Jan 2019) estimates that by 2050, approximately 21.3% of the global population will be 60 years or older. This has led to concerns that there may be an associated significant increase in the prevalence of frailty and mobility difficulties. The World Health Organisation defines frailty as: “a clinically recognizable state in which the ability of older people to cope with every day or acute stressors is compromised by an increased vulnerability brought by age-associated declines in physiological reserve and function across multiple organ systems”. The health and economic impacts of frailty include:

  • increased susceptibility to muscle deconditioning and falls
  • faster decline in levels of functioning and ability to live independently
  • poorer outcomes post- trauma or surgery, with associated increased length of hospital stay
  • long-term disability and increased need for residential and/or nursing care, and associated health and social care costs
  • more frequent and more prolonged hospital admissions
  • increased mortality
“Frailty prevalence at various ages” From British Geriatric Society; “Frailty: what’s it all about?”(May 2018)

Hospital acquired deconditioning is also a significant healthcare challenge. The NHS England End PJ Paralysis campaign (now a global movement) has achieved great progress in raising professional and public awareness of the deconditioning which can result from inactivity during hospital stays for older adults. The End PJ Paralysis website reports that a one week stay in hospital for a person aged 80 can lead to:

  • a 20% loss of power in quadriceps muscles
  • loss of 1.5 kg of muscle mass
  • loss of 10% aerobic capacity

A study by Falvey et al (2015) reported that 68% of patients were discharged below their pre-admission level of function. These patients are 3 times more likely to be readmitted within 30 days. De-conditioning was also found to be a factor responsible for 47% of delayed discharges (Lim et al; 2006).

Fried et al (2001) described frailty using a basis of 5 physical components: weight loss, exhaustion, weakness, slow walking speed, and low physical activity, with individuals being classified as robust if they have none of these components, pre-frail with 1-2 or frail with 3-5 components. Interventions (in primary, secondary and residential care) which can maintain strength, walking ability and physical activity could therefore have potential to remediate or avoid development of frailty. .

There are significant costs associated with frailty, deconditioning and associated health impacts, such as increased risk of falls:

  • Cost of deconditioning and delayed discharges to NHS – £820 million per year
  • Cost of TKR surgery per year – £565 million per year
  • Day cost per bed in hospital - £400 (Ward) or £1500 (Critical Care)

This report focuses on a novel device designed by a physiotherapist in response to a need observed during clinical practice. It has been designed to improve and/or maintain lower limb strength with a view to optimisation of rehabilitation outcomes and prevention of deconditioning due to inactivity.

Current care for prevention of deconditioning and/or rehabilitation for the elderly

Preserving muscle strength and function has many contributing factors; with physiotherapy having a key role. Progressive resistance exercise (PRE) is known to increase muscle strength in even in the frailest individuals (Suetta; 2007) and research suggests that PRE should be used more with older people and in hospitals to improve muscle strength and outcomes (Wiley-Blackwell; 2009, Falvey et al 2015).

Challenges to delivering care in accordance with clinical guidance

A questionnaire survey and face-to-face interviews were completed with Physiotherapy staff in order to gather information on current physiotherapy care for the elderly, challenges to delivering this care, equipment currently used to do this and feedback on the S-Press.

At the time that this report was produced 129 responses to the online survey had been received. (Not all questions were answered by all respondents).

Via face-to-face interviews and questionnaire responses, physiotherapy staff reported that PRE are only infrequently performed with frail elderly patients in usual care either in hospital or nursing home settings. When asked to identify the challenges to delivering physiotherapy to prevent deconditioning, the most prevalent responses were:

  • patient’s anxiety/lack of confidence
  • patient/staff fear of falls
  • patients perceived as too weak
  • lack of time to complete strengthening exercises
  • lack of storage space for equipment
  • lack of sufficient staffing

68% of respondents highlighted a lack of appropriate strengthening equipment as being a major challenge in delivering progressive resistance exercise care.

Some therapists reported use of exercise programmes without equipment, using only the patients’ body and gravity as resistance.

Where specific equipment was deemed necessary, in order to achieve certain therapy goals requiring regulated resistance, the most commonly used equipment included:

  • TheraBands
  • Weights
  • Pedals cycles
  • Continuous Passive Motion (CPM) machines.

Focus groups with physiotherapists on their experience of this equipment provided the following findings:

TheraBands: Although easy to obtain, TheraBands are difficult for many patients to use for leg strengthening as they find it tricky to place and maintain correct position for the bands.

Weights: Problems experienced with some patient groups were reported to include: “the Velcro straps can dig into the skin of frail older patients.” Therapists also reported difficulty in getting access to weights equipment, particularly in nursing home settings.

Pedal Cycles: Although a positive aspect reported concerning this equipment was that Stroke patients were encouraged when able to see affected limbs moving reciprocally (via action of the unaffected limb), again patients were reported to struggle often with “keeping their feet well positioned on the pedals”. Other difficulties reported were difficulty in use with patients who were confined to bed, or for those with “increased tone or ataxia”. One physiotherapist suggested that there was a need for pedal cycles to be improved by providing greater resistance for strength training.

Continuous Passive Motion (CPM) Machines: These were felt to offer help in early phases of rehabilitation, were patients were unable to achieve significant motor control independently, but the machines are expensive and bulky and therefore not available in community settings.

Overview of equipment used for resistance exercise



Therabands are a range of bands, loops and tubing, made of latex or equivalent (for patients with latex allergies).

Available in a range of formats and resistance grades for use in rehabilitation and exercise training to develop muscle strength and range of movement.

Available online for around £10.00 and more specialised versions via NHS Supply Chain - price range £39.00 - £140.00.

Pedal cycles

Pedal cycles

The preferred company for purchase for exercise cycles was reported to be MOTOmed, prices for lower limb rehabilitation devices ranging from £2,100 - £4,700.

A version available for bed bound patients retails at £6,000.

Continuous Passive Motion (CPM) machine

Continuous Passive Motion (CPM) machine

These devices are electronic devices which move knee and hip joints through a controlled range of continuous passive motion. Usually used during the first phase of rehabilitation following a soft tissue surgical procedure or trauma, to increase range of movement while protecting healing tissues. Available via NHS Supply Chain - price range £1,064 - £3,517.

Overview of the S-Press

2022 - NHS tested prototype #5

The S-Press is a portable, lower limb exercise device. It was designed by a qualified physiotherapist in response to a need observed during clinical practice in a range of in-patient, rehabilitation and domiciliary settings.

It utilises a fully covered internal spring resistance system to provide effective progressive resistance exercise for multiple leg muscle groups.

It incorporates a safe, stable foot position and the device meets infection control and tissue viability requirements.

According to individual user requirements, there are 5 easily changeable resistance levels (3kg to 20+kg). The S-Press can be used in sitting or lying position and, due to patent protected fully adjustable, moulded and ergonomically shaped leg rest, with pressure relieving cushioning, the device can also be safely used by patients with heel sores and dressings as the newest version applies no pressure through the heel during use.

Once training has been given, patients are able to use the device independently between physio sessions.

A specialist stroke physiotherapist commented: “many patients admitted onto our wards are acutely unwell. Initially, they are often not ready to receive a lot of therapy input and during this time, as well as recovering from an acute illness, they are at high risk of and often do experience deconditioning. This means that once they are ready for their therapy input to begin they are often weaker than on admission.”

S-Press has been designed to tackle such issues, improve these patients’ outcomes and shorten their length of stay, by maintaining and strengthening the leg muscles of patients who struggle to do standard physiotherapy exercises. This enables the weakest and most frail population the ability to do therapeutic level exercise from a resting position.

The device can be used in two ways, in order to work all the muscles of the lower leg. Pushing the leg forwards along the ‘runner’ works the quadriceps and the gastrocnemius while rotating the device and then pulling backwards works the hamstrings and gluteus.

Other features of the S-Press include a digital repetition counter to help patients track completion of their exercise programmes and also to help maintain motivation.

It also has easy to clean surfaces, in order to comply with infection control regulations.

Features of the S-Press

Unmet Need validation & Stakeholder consultation

This information has been gathered via:

  • a questionnaire designed for physiotherapists
  • a series of focus groups and individual interviews with health professionals, nursing home residents and rehabilitation patients.

Physiotherapy questionnaire

The questionnaire survey achieved a good return rate, with 128 responses received. This included staff within NHS practice (78.5%) and private practice (25.6%).

Of the 128 respondents who answered a question on whether they had patients they felt could benefit from using S-Press, 76.6% felt that they had patients who could benefit. 19.5% were unsure (being keen to have the opportunity to test out the device in their own clinical areas before expressing an opinion). Only 3.9% felt they did not have patients who might benefit. Several of the sites contacted for this evaluation expressed an interest in becoming a trial site for further evaluation of the treatment efficacy, once a sufficient supply of devices has been manufactured in order to facilitate this.

This reflects a significant interest and potential scope for adoption and uptake, pending successful clinical evaluation of treatment outcomes.

Responses on perceived usability of S-Press for different patient groups included the following:

  • 86.8% of questionnaire respondents felt S-Press could be beneficial for deconditioning
  • 81.8% for falls prevention
  • 72.7% for sarcopenia (age related muscle loss)

Other health conditions which were suggested as potentially being suitable were:

  • Care of the Elderly
  • Neurology (including stroke and progressive conditions)
  • Community
  • Orthopaedic Wards
  • Musculoskeletal Outpatient Services
  • General Medical Wards
  • Critical care
  • Spinal cord injury
  • Respiratory medicine
  • Paediatrics
  • Neurosurgery
  • Surgical Wards

Individual interviews

1) Healthcare professionals

Face to face interviews with physiotherapy staff also illustrated positive responses in terms of usability. One physio working in a nursing home context estimated that “around 90%” of his patients would benefit from the S-Press. He felt the device would be particularly useful for patients who have experienced deconditioning during hospital admissions.

Comparing the S-Press device with other resistance exercise equipment, one physiotherapist commented:

“The CPM machines are motorised and so can provide assisted movement – however they are very heavy and not particularly portable. Also, as it is assisted movement its main purpose is to increase range of movement – rather than muscle strengthening, so Strength press could add value to this/ be a focus for the next stage in recovery.”

Another physiotherapist stated:

“I can see it might have the potential to be used by the activity coordinator, as well as in PT sessions - and used independently by alert and motivated patients between sessions.”

Other feedback from physiotherapists included:

“it [the S-Press] is helpful for people who are anxious with even low resistance exercise”. She liked the function available for patients to be able to use it with no added resistance, providing an easier starting point for patients who want to get used to the mechanism or have severe lower limb frailty.
“It looks as though it could be really useful, especially for getting extra practice between therapy sessions. The comparator exercise wise would probably be straight leg raises – but they are done with no resistance, so this would move people further on”.

S-Press was also felt to be potentially useful for patients who, although elderly, were very physically well, active and independent prior to a hospital admission.

A Specialist Orthopaedic Physiotherapist suggested:

“I think it would be helpful with people following a total knee replacement, “for people who are struggling with pain to get up, even getting a bit of resistance exercise through the leg to get a bit of confidence, circulation, everything really, all the stuff we look to achieve through early mobilisation, can hopefully be achieved through this [the S-Press] rather than just CPM.”

A Nursing Home manager (of a 63 bedded home) stated:

“I can see that it would be useful – particularly on evenings and weekends, as at the moment residents feel like there isn’t anything for them to do – we could probably do it with them.”

Another Care Home manager stated:

“I think it would be kept in the therapy office and then, once PTs have assessed, it could be in residents’ rooms during use.”

In general, health care professionals felt S-Press could potentially be used: by the activity coordinator, qualified physiotherapists, physiotherapy assistants and (following training) used independently by alert and motivated patients between sessions.

2) Patient feedback

DC, 93: recovering from a hip fracture, said:

“it would have been ideal when I could walk less” (this person had been frustrated during the acute phase of a recent stay on an acute hospital ward at the amount of face to face time with physiotherapists).

The theme of frustration around limited face to face time with therapy staff was also commented on by SM, 30:

“I think this would be good, because although I have PT here it isn’t consistent and they are not there at the weekend. So, like, last week – Friday, Saturday, Sunday and Monday I had nothing.” He also liked the design of the device: I have used the pedal cycle but it’s very unstable cos it moves so I can’t really use it. This definitely looks way more stable. I think as well that the pedal cycle has the potential to rub the inside of the other leg. With this I don’t think there would be any chance of rubbing the other leg. I think this would help me make progress more quickly.”

GC, 93:

“I have a set of Therabands at home that I use. I think I would be able to use this also.”

GS (81) said she liked the idea of the S-Press as:

” [she] could do it in her wheelchair on top of the therapy that I receive twice a week. I just want to get better”. When asked about the look of the S-Press, she said “I am more bothered it does the job than look a certain way”.

Another nursing home resident commented that she found the S-Press

“looks easy to use and supportive on the feet.”

A lady with Multiple Sclerosis commented:

“I love it, I absolutely love it for that there are so many people who lay in bed and do nothing, I spend a lot of time in hospital and it’s the lack of exercise and lack of activity that I think is so destructive, muscle wastage and muscles reduce so quickly and so anything to enable people to have some sense of activation, motivation or some sense of achieving something I think is hugely valuable. I think it is wonderful because it’s a simple idea for people to actually do something as opposed to just sitting there and waiting for their bodies to recover.”

Stakeholder analysis

We asked healthcare staff (via focus groups, interviews and the questionnaire) a range of questions designed to ascertain how they make their equipment use decisions. Responses indicated that most physiotherapists would find a price point at £500, or below, affordable with 18% of people answering £100 or less, 39% of people answering £100 - £500, 25% said £500-£1000 and 18% said £1000-£4000.

Factors considered by physiotherapists in selecting therapy equipment

We asked in the physiotherapy questionnaire what factors they consider when purchasing therapy equipment. Responses were:

  • Research evidence (78.2%)
  • Ease of obtaining [the kit] (63.9%)
  • Performance reviews (57.1%)
  • Likelihood of patients performing exercises (53.8%)
  • Weight (50.4%)
  • Training that staff or other carers would need (47.9%)
  • Fitness for purpose for individual patients’ needs (36.1%)
  • Cost (21.5%) - noting that 72.5% of respondents were not responsible for equipment purchases.

Groups identified as potential purchasers of the device include:

  • Physiotherapy departments (NHS and Private sector)
  • Hospital In-Patient Wards: including orthopedics, care of the elderly, general medicine, general surgery, respiratory medicine, critical care, burns and plastics, Spinal Injury and Pediatrics
  • Intermediate Care Rehabilitation Units
  • Stroke Rehabilitation Units
  • Residential and Nursing homes (Social Services and Private Sector)
  • Private purchase by older adults in their own homes

Based on the physiotherapists’ responses, unique selling points that may appeal to therapy staff in addition to research evidence, performance reviews, and training include:

  • Fewer staff needed to operate the equipment
  • Less supervision required by physiotherapy staff
  • Versatility
  • Portability and storage
  • Cost
  • Patient-perceived appeal

Safety and Regulatory Considerations

The S-Press complies with NHS tissue viability and infection control policy and has undergone successful independent durability and safety testing. A technical file is being compiled in order to complete CE marking processes.

Funding Awards to date

S-Press has already been successful in competitive funding awards. To date this has included:

  • £5,000 from innovate UK to cover concept development work and initial prototyping
  • £5,000 from Versus Arthritis in a joint pre-accelerator competition with the Design Council
  • £1,000 Sheffield City Innovation Grant
  • £87,000 Follow On funding from Versus arthritis for iterative prototype development
  • £1,000 funding from the Council for Allied Health Professions Research (CAHPR) for co-design focus group work for patient and public involvement and work to identify design requirements for tissue viability and infection control aspects

Intellectual property

S-Press has been registered as a Trademark and a UK Patent has been awarded. Design elements have been registered and an application submitted for an International Patent.

Jennifer Turner is the registered owner of all background Intellectual property to the date of this report.


Evidence will be required regarding feasibility, usability and clinical efficacy of this device and value for money for potential purchasers. In order to facilitate a broad scope of potential patient suitability, feasibility and usability will need to be demonstrated for each suggested mode of use - i.e. with patients sat in a chair and also use for patients on air and normal pressure mattresses. Information on usability for patients with potential challenges to use of this type of device would be helpful - for example, patients with cognitive and/or communication challenges, patients with fragile and/or sensitive skin and any patient weight/leg girth advisory restrictions.

Plans already in place to progress towards gathering this evidence include and application for funding for a clinical trial, which will include health economic evaluation as well as patient health outcomes.

Potential health economic indicators might include:

  • Reduced length of stay
  • Efficiency savings for physiotherapy departments, due to the use of S-Press by other staff groups and Independent use by patients

Potential patient health outcomes might include:

  • Increased strength and range of lower limb movement
  • Increased muscle mass in targeted muscle groups
  • Maintenance of muscle mass in targeted muscle groups (avoiding sarcopenia)
  • Increased exercise time

D4D would also recommend that clinical trials incorporate a PPI trial planning stage where patients have the opportunity to define the outcome measures that are of importance to them, factors which might influence their motivation to complete exercises, review of patient information resources (for device use and also trial participation) and to check for any other relevant patient perspective information.