The authors declare no conflict of interest.
Persons with osteoarthritis often have signs of reduced muscle strength. Some studies suggest that this strength could be improved with exercise. However, does this form of therapy improve the disease status as assessed by improvements in cartilage viability, a hallmark of the disease? This brief describes the possible usage of exercises in general, plus those known to improve strength and function, and reduce pain and whether structural impacts that favor or impede disease regression have been observed in this context among the older osteoarthritis adult population. Since exercise may also do harm, rather than good in osteoarthritis management if excessive, contra indicated, or suboptimal, what is the consensus in this regard in 2024?
Osteoarthritis, the most common rheumatic disease is a chronic condition affecting the majority of the older population. Commonly deemed incurable, osteoarthritis is a well documented and frequent source of functional disability and pain despite years of research and intervention attempts. In the context of the increasing aging populations worldwide, the collective costs of the disease, considered as a key determinant of an age related intrinsic capacity decline
Commonly characterized by progressive bone remodeling, bony outgrowths, and micro fractures, cartilage tissue fragmentation and degeneration, plus possible joint capsular fibrosis, ligament instability, muscle pathology, and often joint derangement and instability, osteoarthritis joints may become poorly aligned and more susceptible to cumulative or sudden joint impact forces with dire functional consequences
On the premise that exercise will delay muscle atrophy
Based on a sample of parallel reports it can argued that exercising can place widely varying biomechanical and physiologic demands upon the cartilage tissues and its cells and fibrous supportive surrounding matrix that may or may not stimulate cellular biosynthesis, which is the basis for the adaptation and viability of this important joint shock absorbing tissue lining
However, in addition to observations that support modest exercise as a beneficial cartilage mediating strategy, that observed in light of the above mentioned potential research limitations, plus those denoting no adverse or favorable cartilage based impact in the context of a single exercise bout in severely damaged knees prior to surgery
This present overview aimed to examine whether exercise as applied to osteoarthritis has any impact on cartilage tissue assessed directly through radiographs, the gold standard measure in this respect. As well, resistance training in the form of isometric exercise, one of the oldest forms of exercise used for arthritis management was specifically examined and if so what radiological or its proxy measures as assessed through serum measures, biomechanical, or force measures indicate in this realm and in what regard.
The review attempted to establish whether exercises that have been studied for many decades appear to reduce joint attrition and its progression objectively, while increasing increase muscle power and function safely and significantly in osteoarthritis contexts.
In light of the continued osteoarthritis disease burden that is increasing rather than decreasing, along with the current emphasis on applying evidence based medical recommendations in all spheres of endeavor, versus hearsay or traditional approaches, it appears reasonable to ask if the lack of solid evidence that exercises can be applied successfully without any discrimination or on the basis of the prevailing studies to improve osteoarthritis wellbeing is based on sound science and/or takes into account its variable pathology, sub groupings, and characteristic features of osteoarthritic joint change. These features include: progressive bone and articular cartilage degenerative changes, capsular fibrosis, ligamentous damage, joint laxity, sensory (mechanoreceptor) receptor changes and extensive muscle pathology. Joint inflammation is also a consistent feature of along with pain, joint effusion, stiffness, decreased range of joint motion, muscle weakness, joint instability and deformity, and progressive reductions in the efficiency of musculoskeletal functioning. But, the question arises as to whether as applied to the older adult population, whether exercise is a panacea or can a failure to act cautiously in exercise applications in the presence of osteoarthritis induce more rather than less disability and adverse psychosocial reactions and thus more costly outcomes
As well, since even modest stretching exercises may prove injurious, for example in cases that are neuropathic
The question of whether exercise has a uniformly beneficial impact on an osteoarthritis joint in the older population is topic that warrants more scrutiny in our view because even though multiple affirmative studies imply a significant pain relieving benefit, surgery continues to be demanded by those who may have pursued exercise diligently. This may be because muscles and their physiological and structural attributes may be dysfunctional to a considerable degree in a high percentage of osteoarthritis subjects and thus benefits from exercise applications may not align with those observed in the lab. Moreover, exercise that is poorly designed or supervised
A comprehensive overview of peer reviewed publications posted on
Considering the plethora of exercise associated studies cited on the three data bases currently examined, and the mostly mixed samples, study designs, and modes of treatment but few analogous or replication studies or consistent themes of exploration, we elected to focus on examining both exercise impacts in general as well as resistive modes, as observed in randomized controlled trails, and often advocated for treating arthritic joints because they involve muscle contraction without producing joint motion, and in the belief that transarticular forces can be duly minimized as result. Brown et al.
Even when earnestly sought, and regardless of data base employed, it was unusually challenging to delineate or even uncover the potential impact of formal exercise in any form on osteoarthritis associated joint structures of any sort, and what actual post exercise functional results were observed. Almost none assessed any probable joint soft or hard tissue impacts or status directly or even indirectly, and in those studies using multiple intervention formats results could not be attributed to exercise per se in many cases with any degree of certainty. Moreover, rather than testing the most widely employed and recommended forms of exercise for arthritis, most current studies failed to apply isometric exercise methods of various doses and combinations and were not those that could be readily subsumed by most older adults, such as eccentric high intensity exercises.
As well, there was little evidence regimens studied were applied with the goal of maximizing one or more outcomes based on the specificity of exercise theory, wherein exercise has both general, as well as specific effects on muscle that can be optimized. By employing vastly differing subject groups with varied degrees of osteoarthritis, where most over age 80 were not included in the study, as well as largely subjective measures, and few objective outcome assessments, loading estimations, biochemical, neuromotor, kinematic, and radiographic baseline and outcome measures, with few exceptions (eg.,51 -54) it is impossible to state that exercise is universally beneficial and its effects are similar no matter how these are applied. In addition, among the many research reports reviewed, most pertaining to exercise focused on the knee joint, with few exceptions. Even in this case, where the consensus remains that pain and function improve no matter how exercise is practiced or how often
Since osteoarthritis is a complex disease with many overlapping features, the assumption that all exercises are equal in impact as well as beneficial or safe in all forms and stages of this disease must be questioned given most researchers failed to confirm the presence or absence of any accompanying joint loading improvements or non improvements or worsening of joint structural stability plus inflammation, and disease biomarker status. The associated relevance of extraneous variables such as obesity, muscle metabolic and structural post exercise alterations
At the same time, even if deemed high quality as far as research design goes
Moreover, in accepting that more cases performing exercise will have less osteoarthritis pain than not, no matter how this is approached
Unsurprisingly, even in the realm of some key resistance or alternate exercise modes applied in a controlled manner, results remain challenging to aggregate, hard to validate, and apply with any degree of certainty. Not only do exercise approaches differ considerably, but whether these result in disease modifications that are measurable objectively, and that could help identify salient underlying explanatory and disease mediating mechanistic processes, for example the observed lack of exercise impacts on the osteoarthritis knee adduction
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|---|---|---|---|
| Baker et al. |
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+ improved pain, function, strength, life quality | x |
| Bruce-Brand et al. |
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+ equal functional benefits, cross sectional area muscle/strength | x |
| De Zwart et al. |
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+ pain, function, mostly equal results | x |
| De Vita et al. |
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+ strength/pain, no biomechanical effect | x |
| Holm et al. |
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+ strength, function | x |
| Huang et al. |
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+ pain, function | x |
| Messier et al. |
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- pain, function, joint status equal | x |
| Kus et al. |
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+ pain, function, equally | x |
| Oğuz et al. |
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+ pain, function, equally- cartilage metabolisms changes | Y |
| Øiestad et al. |
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+ muscle strength, VO2 max- no quality of life benefit compared to standard care | x |
| Onwunzo et al. |
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+ pain intensity, range of motion, functional ability | x |
| Vincent et al. |
4 m |
+ pain, function equally | x |
| Yabroudi et al. |
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+ pain and function improved equally | x |
Abbreviations: + improved; - not improved/altered; m=months; wk: weeks; yr(s)=year(s)
In addition to the snapshot above, and even when considering all currently published exercise oriented osteoarthritis meta-analyses and research studies of note it appears that despite years of endeavor no single form of exercise is found to consistently produce a pain free result for all osteoarthritis cases or appears to be of the highest merit overall. Additionally, even if sample sizes that are modest at best are discounted as non representative of the population, and very few attempts at sub group assessments are evidenced to date, why some cases respond favorably or unfavorably to exercises in general, as well as specific modes of exercise in this regard
At the same time, outcome indicators that might reflect the disease characteristics more closely than not are often not detailed. These might include, but should not be limited to factors such as:
a. the degree of joint effusion,
b. joint range of motion,
c. muscle fiber size and composition,
d. muscle recruitment patterns,
e. inflammatory biomarkers,
f. body mass,
g. functional kinetic and cognitive features,
h. actively assessed aerobic capacity.
Additionally, attempts to overcome the presently vastly differing intervention frequency, duration, and intensity approaches to exercise that exist along with limited follow-up accounts of their impacts on key structural joint features and others are hard to generalize
In sum, despite the goals of most clinicians – what should be done or undone or avoided when assessing a specific client’s exercise needs cannot be discerned with any degree of predictability as beneficial or optimally beneficial and safe or appropriate for achieving a set of desired outcomes
To advance this line of inquiry where systematic reviews do not always concur or fail to assimilate comparable data, we propose that dedicated study is warranted here so as to protect the vulnerable older adult with osteoarthritis from a low life quality as well as from probable increasingly adverse cartilage tissue and joint impacts as based on animal models subject to subnormal joint loads. Applying similar methods to those used in the lab including more careful study selection criteria and controls plus advanced clinical and biological as well as imaging data over time relative to baseline and patient characteristics would appear to hold great promise. In particular, as attempted by Lange
As well, since most older adults diagnosed as having osteoarthritis will likely differ in multiple respects
Even if exercise is underrated, without adequately supportive robust definitive data, the belief osteoarthritis is not curable and movement participation has no effect or can in fact worsen its presence may persist. Either way, patients may either avoid exercise or try to adopt regimens that may place undue loads on their already fragile joints and cartilage matrices, such as running or yoga or those widely touted without any validated evidence by the media, those who ‘sell’ exercise equipment or gym memberships, and science based public health preventive messages that may not be evidence based or easily performed in the home environment or nursing home, such as aerobic aquatic or resistance exercises in a pool
Although osteoarthritis has been studied for more than a century, the disease appears to be more common today than ever, and remains the leading disabler of older adults. Often denoted as a disease of the articular cartilage, the tissue lining the ends of bones of freely moving joints such as the knee, this report sought to evaluate the known effects of exercise-almost universally recommended for osteoarthritis care, on measures of cartilage structure that represent the state of attrition or degradation. Exercise was analyzed because it is widely touted as being of value to the patient, and where sedentary behaviors plus muscle weakness may impair overall function and induce inflammation, dysfunction, and pain. Based largely on animal models of osteoarthritis such as the rat exposed to various exercises in those with artificial arthritis
Based on the functional requirements of persons with osteoarthritis, as well as the limitations imposed by their joint pathology, it explored if exercises safely improve function and reduce pain in all osteoarthritis cases, and the degree to which this approach can impact its articular cartilage structural features favorably.
Although delimited to: studies of osteoarthritis in the older population this review reveals that despite widespread generic calls across the globe for exercise training and participation for fostering the health of older adults ideally including a combination of aerobic, muscle strengthening, and flexibility exercises for the older or aging adult, this approach may be ill considered for ameliorating cartilage attrition in the sedentary older adult with severely painful osteoarthritis, even if strongly recommended by osteoarthritis experts and others
At the same time although we did review the most extensive medical data sources and those housing meta analyses and conclusions reached by leading reviewers, the body of related meta or umbrella exercise training analyses may not be robust in all respects, nor comparable. They may not for example, provide clear data on adherence issues (eg., 64), nor possible timely data as most reviewed studies were conducted in eras where obesity was not rife (eg., 24) using secondary data sets applied in a single location, and where data collected was largely subjectively assessed
Why one type of exercise is chosen and not another and how one form of exercise impacts osteoarthritis joints other than the knee or explains non uniform as well as uniform outcomes in varied osteoarthritis studies is consequently very hard to unravel
In addition, exercise carried out in the absence of patient education
Indeed, perhaps older adults with osteoarthritis are suffering in excess because even with over 100 exercise based therapy studies espouse benefits on pain and function, they still fail to provide indisputable evidence that pain relief in osteoarthritis and exercise are robustly linked
Rather, there is an assumption of a ‘one size fits all’ osteoarthritis diagnoses, and that its association with exercise is a linear and a universally conclusively favorable one
In the interim, function, functional performance and life quality as well as research quality in exercise based assays remain questionable at best despite numerous study attempts
Alternately, the costs of failing to do this can be expected to rise in multiple ways and especially if exercise impacts on function and life quality cannot be validated and exercise dosages applied that do have a bearing on osteoarthritis pathology remain unknown. In addition costs will rise if for example, only a small number of cases over time appear to do better than those who receive no treatment, or where treatment or its impact is suboptimal, ineffective, or possibly harmful or determined by type or groupings of osteoarthritis
While no simplistic approach will be enlightening on its own, to make some headway in this complex realm, in tangible ways, perhaps the use of small workshop collectives, single case studies, and careful ‘n of 1’ single subject design efforts or follow ups of current study participants over time, can generate some helpful insights and enlightening data. In addition to careful sample selection, efforts directed towards reducing potential measurement errors, combining animal and human related studies, employing artificial intelligence diagnostic assessments AI and others using agreed upon sensitive assays and parameters that allow for advanced statistical analysis of the included demographic, clinical, radiographic, and musculoskeletal profiles are especially recommended.
To avoid provoking excess or preventable disability and pain and the undue expenditure of energy required by some forms of exercise, and that could reduce overall functional performance capacity, it appears careful evaluation and applications of supervised exercises of modest intensity that are not impactful on the joints of the older adult with osteoarthritis and that builds on what we know can be helpful, and should be based on clinical indicators as well as radiographic, imaging, neuromotor, biomechanical and biochemical measures.
As opposed to a failure to do this, a comprehensive effort at baseline and follow up may make the difference between the immense benefits of ‘precision’ versus ‘generic’ medicine approaches that may not work for all older osteoarthritis cases.
As observed by Kong et al:
Based on our concerted effort to access and synthesize or uncover any specific trends or clinically relevant observation between exercises and radiological or disease markers in older adult populations with osteoarthritis, what is clear is the absence of such data as well as many less than robust clinical trials on varied rather than a single intervention strategy, thus claims that exercise of any mode is beneficial or harmless cannot be totally justified in our view.
We further conclude that to foster as well as forge more firm and robust conclusions about the scope of exercise and its bearing on osteoarthritis degradation, experts in the field, clinicians and others should brook no further delay and engage interactively to support multi centric long-term larger studies to examine and validate all the nuances of the phenomenon of supposed disease modifying influences of exercise on articular tissues in both treatment successes as well as failures so as to help identify best evidence based patient directives and the utility of adopting one or more regimens of exercise by older adults with diverse forms of osteoarthritis pathology.
To this end, we propose more efforts to carefully consider the fact that a one size fits all approach is actually foreign to other medical realms such as heart disease, osteoporosis, stroke, rheumatoid arthritis, and respiratory ailments. Additionally efforts to integrate biomechanical and laboratory measures into the evaluation of osteoarthritis cases before advising them to exercise are strongly indicated.
In the face of the mounting older population and their susceptibility to this currently incurable degenerative joint condition termed osteoarthritis, we urge the dedicated researcher and clinician to forge a pathway that can add to and shed light on the existing evidence base upon which family practitioners and others can better rely and act safely and efficaciously using strategies consistently found to be restorative, regenerative, life affirming, or preventive.