The scale of the problem the guideline addresses is enormous. In the European Union alone, an estimated 22.1 million women and 6.6 million men aged fifty and older were living with osteoporosis in 2019, and 4.3 million new fragility fractures were reported that year. Germany carries a heavy share of this burden: roughly 4.5 million women, or 22.6 percent of the female population, and 1.2 million men are affected, together accounting for about 6.1 percent of the total population. A demographic simulation model projects that fractures attributable to osteoporosis in Germany will climb from 115,000 in 2010 to 274,000 in 2050, accumulating roughly 8.1 million fractures over that period and discounted costs of 88.5 billion euros.

What makes these numbers so troubling is that a proven countermeasure already exists. A substantial body of evidence shows that physical exercise, when properly designed, strengthens the muscular system, improves balance, and reduces the risk of falls and fall-related fractures in older adults, including those with confirmed bone loss. Patients with suspected or confirmed osteoporosis are routinely referred to physiotherapy to tackle fall risk, pain, restricted range of motion, posture, and declining physical function. Yet until recently, German physiotherapists had to work from the interdisciplinary 2023 national osteoporosis guideline, which offers only a few general statements about physiotherapy, or from a 2009 physiotherapy guideline that was never updated.

Building a brand-new guideline from scratch demands years of work, deep expertise, and considerable funding, so the team chose a smarter route: guideline adaptation. This internationally recognized approach takes an existing, high-quality guideline from another country and carefully reshapes it for a new healthcare context. The researchers structured their project around six modules, informed by the ADAPTE Collaboration framework, a methods paper from the German Society for Physiotherapy Science, and established procedures for cross-cultural adaptation of health measures. The study protocol was published prospectively on the Open Science Framework before the work began, and the project received ethical approval in Germany.

The first three modules formed a methodical search-and-select pipeline. Following the PRISMA 2020 reporting standards, the team searched three scientific databases, including MEDLINE, PEDro, and Web of Science, plus nine international guideline databases and relevant professional websites. They screened 873 records in total, 207 from databases and 666 from other methods, applying strict inclusion criteria: the document had to be a comprehensive guideline written specifically for physiotherapists, focused solely on osteoporosis management, published in German or English within the previous five years, and of acceptable methodological quality. Two reviewers screened independently at both the title-abstract and full-text levels, resolving disagreements through discussion.

Two candidates survived the funnel: the 2022 guideline from APTA Geriatrics, the Academy of Geriatric Physical Therapy of the American Physical Therapy Association, authored by Gregory Hartley and colleagues, and the 2022 UK consensus statement on physical activity and exercise for osteoporosis by Brooke-Wavell and colleagues. Both were appraised with the AGREE II instrument, the international gold standard for guideline quality, which rates 23 items across six domains including rigor of development and editorial independence. The American guideline scored 50 percent overall, the UK statement 58 percent, but the APTA Geriatrics document performed better on the two decisive domains, rigor of development and editorial independence, and was selected for adaptation.

Translation came next, and here the team embraced a strikingly modern technique. Rather than relying on a single human translator, they ran the English guideline through two artificial intelligence systems, the Perplexity AI search engine and the neural machine translation service DeepL, producing two independent German versions. Two researchers then synthesized these into a first draft, flagging every word or sentence rated critical or unclear. The draft, along with both AI translations and the original English text, went to a four-member expert committee: two clinical specialists in geriatric physiotherapy and two methodological experts in guideline development, who assessed linguistic accuracy, medical terminology, fit with the German healthcare system, and consistency with the 2023 German interdisciplinary osteoporosis guideline.

A virtual consensus meeting produced a second draft, which then faced its toughest critics: the people who would actually use it. Three practicing physiotherapists, aged 26 to 34 and treating between 2 and 50 osteoporosis patients per month, reviewed the draft for comprehensibility, readability, and feasibility, and gave interviews lasting up to 47 minutes. Two women with osteoporosis, aged 75 and 80, also reviewed the recommendations section. Their feedback drove concrete changes: a definition of impact training was added to a new glossary, the colors distinguishing different exercise types were made more contrasting and red and green were avoided to help visually impaired readers, and the potentially confusing pronoun we was replaced with neutral wording. The patients found the recommendations generally feasible, though some, such as progressive resistance training and jogging, exceeded their personal health restrictions, which the team judged to be individual limitations rather than flaws in the guideline.

Critically, none of the clinical recommendations themselves were altered. The adaptations were contextual: a note pointing German readers to national fall-prevention training recommendations from the Federal Initiative for Fall Prevention, a glossary defining terms such as low-trauma fracture and weight-bearing exercise, color-coded exercise categories, person-first and gender-conscious language, and the omission of the original implementation chapter, which described the American healthcare system and did not transfer. The original guideline’s developers reviewed and approved every change, and the final German version was signed off by the entire research team. It is now available open access on the Open Science Framework, and the team has announced it through national physiotherapy associations, published an accompanying article in a clinical journal, and launched an educational course already delivered in two German physiotherapy clinics with promising evaluations.

The project also reveals an interesting divergence within German-language guidance. A newly published guideline from the osteology umbrella association DVO on physical exercise for fracture prevention clearly recommends high-intensity strength training and impact loading such as jumping and rapid stair climbing where individually feasible, while the adapted APTA Geriatrics guideline is more cautious, emphasizing individual fracture-risk stratification and tailored loading. The two documents contain no fundamental contradiction; they simply emphasize different things, one focusing on what is effective and the other on identifying who should do it and under what safety conditions. Together they give German-speaking physiotherapists a two-pillar evidence base. The authors are candid about limitations, including an unupdated search, a small user-review panel, no formal back-translation, and the source guideline’s own reliance on evidence ending in 2018. Still, the work stands as a template: it shows that careful, participatory adaptation, with AI translation as a starting point rather than a shortcut, can move trustworthy clinical evidence across languages and health systems, and it hands millions of patients with fragile bones a far better chance that the therapy they receive matches the best science available.

Subject of Research: German translation and contextual adaptation of a US clinical practice guideline for physiotherapy management of osteoporosis

Article Title: Physical therapist management of patients with suspected or confirmed osteoporosis – German translation and contextual adaptation of a clinical practice guideline from the Academy of Geriatric Physical Therapy (USA)

Article References: Braun, T., Hermanns, M., Haug, V., Nau, J., Scheffler, B., Diermayr, G., Hartley, G. W., Avin, K. G., & Saal, S. (2026). Physical therapist management of patients with suspected or confirmed osteoporosis – German translation and contextual adaptation of a clinical practice guideline from the Academy of Geriatric Physical Therapy (USA). Frontiers in Rehabilitation Sciences, 7, Article 1933821. https://doi.org/10.3389/fresc.2026.1933821

Image Credits: AI Generated

DOI: 10.3389/fresc.2026.1933821

Keywords: osteoporosis, physiotherapy, clinical practice guideline, guideline adaptation, fracture prevention, exercise, AGREE II, ADAPTE, machine translation, geriatric rehabilitation, Germany, fall prevention

The study, led by Suzanne M. Debeij of Leiden University Medical Center and colleagues, is part of a larger multicentre cohort project called Better@Home, which followed 110 patients across eight Dutch geriatric rehabilitation centres. For the sensor sub-study, the researchers recruited 26 patients from a single rehabilitation centre in an urban area, along with nine care professionals, most of them physical therapists. The participants were typical of the geriatric rehabilitation population: the median age was 77 years, roughly six in ten were women, and most lived alone. Their reasons for rehabilitation ranged from elective orthopaedic surgery and trauma to respiratory disease, and they spent a median of about 25 days as inpatients followed by roughly 46 days of home-based rehabilitation.

The technology at the heart of the study was the Hipper sensor monitoring system, a hip-worn device containing a three-dimensional accelerometer that samples movement 12.5 times per second and produces an activity output every minute. That output is expressed as a Physical Activity Measure, or PAM score, which reflects the amount of body movement recorded and can be converted into metabolic equivalents for analysis. Data travel wirelessly from the sensor to a Raspberry Pi-based transmitter and then to web dashboards accessible to both patients and care professionals. Crucially, the system was not just a measurement tool: therapists were expected to use the data to coach patients about their movement behaviour, often during regular therapy sessions. Three versions of the sensor were used during the study period, including an updated prototype that provided minute-by-minute rather than 15-minute output and required redesigned dashboards.

The researchers assessed usability and feasibility using a mixed-methods design. A focus group with the care professionals was structured around the User Experience Honeycomb model and analysed with the qualitative Framework method, while patients completed interviewer-administered surveys at admission and after discharge. Quantitative adherence came from the sensors themselves, with wear days counted as a measure of how consistently the system was actually used. This triangulation allowed the team to compare what professionals and patients said about the technology with what the devices recorded in practice.

The adherence numbers were striking. Twenty-three patients wore the sensor during inpatient rehabilitation for a median of 11 days, corresponding to 100 percent of the days the sensor was offered. During home-based rehabilitation, 19 patients used the device, wearing it on 96.6 percent of the days it was available. For a population characterised by frailty, multimorbidity, and often some degree of cognitive impairment, those adherence rates are remarkable and suggest that, at a basic level, the system worked as intended. The researchers concluded that feasibility — the extent to which the digital health system functions as intended — was sufficient, though they caution that high adherence may partly reflect compliance with clinician instructions rather than genuine engagement with the technology.

What the sensors recorded, however, was sobering. During inpatient rehabilitation, patients spent a median of 93 percent of their waking day — about 666 minutes, or more than 11 hours — in sedentary behaviour. At home, the proportion dipped slightly to 90.5 percent, but because total wear time increased, the absolute sedentary time actually rose to a median of about 704 minutes per day. Time spent in moderate-to-vigorous physical activity was essentially zero in both settings, at 0.0 percent of waking time, while light physical activity accounted for only about 7 percent in hospital and roughly 10 percent at home. The pattern of sedentary bouts did shift between settings: patients had more frequent but shorter sedentary episodes at home, and time spent in uninterrupted bouts longer than an hour decreased by nearly 48 minutes.

These findings matter because prolonged sedentary behaviour is not a benign habit. It is associated with increased risk of non-communicable diseases and all-cause mortality, even in older adults who meet recommended physical activity guidelines, and it may delay functional recovery, worsen deconditioning, and increase dependency in daily activities. Both total sedentary time and long, uninterrupted sedentary bouts contribute to the harm. For frail older patients, simply breaking up sitting with short, low-effort movements may be a more realistic starting point than pushing them toward higher-intensity exercise — which is precisely the kind of behavioural nudge that monitoring-and-feedback systems are designed to deliver.

Yet the qualitative data revealed why the system struggled to fulfil that promise. Care professionals valued the sensor as a conversation starter that opened meaningful, motivational discussions and offered insight into when and how intensely patients moved — one therapist described being able to see whether a patient practised all morning and then did nothing in the afternoon. But they were troubled by the opacity of the PAM score, which patients could not interpret, and by perceived measurement inaccuracies that eroded trust in the data. One physiotherapist recounted a patient who was offended when the sensor failed to record her climbing the stairs, even though she had been working hard. The denser data streams from the updated sensors made the dashboard graphs more complex and harder to interpret, and practical frictions — the risk of losing the device, logistical hurdles, and the many steps required to enrol and transfer patients between settings — further impeded integration into clinical workflows.

Patients echoed many of these concerns. Thirteen of the fifteen who answered the sensor-related survey questions said the system offered them no added value, and only seven said they fully or partially trusted the sensor. Some were unsure why they were wearing it at all, with answers ranging from “for research” to “I don’t know, I’m in a wheelchair.” Nearly half reported that their care professionals did not provide adequate support, and several wished they could review the results together with a therapist. Still, the picture was not uniformly negative: eight patients found the system easy to use, five said they would recommend it, and one noted that it created a sense of external accountability for staying active.

When asked what a better intervention would look like, the professionals were clear: it should be easy to use, have a clearly defined objective, incorporate technology that provides direct visual or tactile feedback, and show patterns, intensity, type, and timing of activity over time. They also stressed preconditions that go beyond the device itself — educating patients and informal caregivers about the risks of sedentary behaviour, conducting a pre-implementation analysis of needs and available technology, involving the entire multidisciplinary team, and cultivating a rehabilitation climate that invites and makes it safe to be physically active, with staff acting as role models. The study’s authors conclude that sensor-based feedback in geriatric rehabilitation can indeed be feasible and valuable, but only if measurement accuracy improves, the technology is tailored to individual patient goals, its added value becomes evident to users, and support is provided to both patients and professionals. In other words, the hardware may be ready; the harder engineering challenge is human — designing eHealth that fits the routines, abilities, and motivations of the older adults and clinicians it is meant to serve.

Subject of Research: Usability and feasibility of wearable sensor-based feedback on sedentary behaviour in geriatric rehabilitation

Article Title: Usability and feasibility of a wearable sensor-based monitoring system providing feedback on sedentary behaviour during inpatient and home-based geriatric rehabilitation

Article References: Debeij, S. M., Haaksma, M. L., de Waal, M. W. M., van Haastregt, J. C. M., Pol, M. C., Kasteleyn, M. J., & van Dam van Isselt, E. F. (2026). Usability and feasibility of a wearable sensor-based monitoring system providing feedback on sedentary behaviour during inpatient and home-based geriatric rehabilitation. European Geriatric Medicine. https://doi.org/10.1007/s41999-026-01616-6

Image Credits: AI Generated

DOI: 10.1007/s41999-026-01616-6

Keywords: wearable sensors, sedentary behaviour, geriatric rehabilitation, eHealth, physical activity, older adults, feasibility, usability, behaviour change, digital health, home-based rehabilitation, patient adherence