Study analysis · BMC Sports Science, Medicine and Rehabilitation · 2026
Slow lifting or slow lowering? For knee arthritis, both helped—but the study can't prove they're equal.
In 56 women with knee arthritis, 12 weeks of slow weight training improved pain, function, and strength whether they focused on lifting or lowering, with no clear winner.
Overview
What the study found
The study in plain English — the bottom line, every takeaway we extracted, and what to do with them.
In simple terms
This study randomly put women into two exercise groups and checked if they felt better after 12 weeks. Both groups improved, but there was no group that didn't exercise, so we can't tell if the exercise caused the improvement or if it would have happened anyway. It also doesn't prove that one exercise is as good as the other.
What’s the bottom line?
Researchers tested two types of slow resistance training in older women with knee osteoarthritis. Both types helped reduce pain and improve function and strength over 12 weeks, but neither was clearly better than the other.
How strong is this study?
The study did some things well, like randomly assigning people and having the person measuring results not know which group they were in. But it was small and had no control group, so the results are not strong enough to say the exercises definitely work. We also only have a short summary, not the full details.
0 / 100
- COI disclosureconflicts of interest not disclosed
- Data availabilitydata not shared
- Code availabilitycode not shared
55 / 100
- Randomization+20/20
- Blinding+9/15
- Control groupno control group
- Sample size (n=56)+4.9/20
- Follow-up+10/10
100 / 100
23 / 100
- P-values+15/15
- Effect sizeno effect size reported
- Confidence intervalsno confidence intervals
- Pre-registrationnot pre-registered
Each component is scored out of 100 and then capped by the study design — a case series cannot reach the ceiling a randomised trial can, however well it is reported.
Where it sits
RCT reviewsReviews of RCTs (Meta-analyses)
Max 100Randomized TrialsRandomized Trials
Max 90Reviews of Cohort StudiesReviews of Cohort Studies
Max 85Cohort StudiesCohort Studies
Max 72Reviews of Case-Control StudiesReviews of Case-Control Studies
Max 63Case-Control StudiesCase-Control Studies
Max 58Cross-Sectional & Case SeriesCross-Sectional & Case Series
Max 50Expert OpinionExpert Opinion
Max 545 / 100
Probability of being correct
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
This design cannot establish causation — the findings describe an association, not a cause. No non-exercise control group; within-group improvements cannot be attributed to the intervention. No significant between-group differences were detected, and the trial is underpowered for equivalence. Abstract-only report limits verification of methodology.
COI Unknown
Could not determine conflict of interest status
No conflict of interest or funding statement was provided in the abstract; COI status and funding sources cannot be determined.
Abstract only; no COI or funding section. Trial was retrospectively registered (UMIN000060649), which is a separate transparency concern but not a COI. No author affiliations are provided.
Key takeaways
- 01
Both groups improved in pain, physical function, muscle strength, and muscle mass (p<0.05).
- 02
No significant difference between groups.
- 03
Effect sizes not reported.
- 04
The study didn't compare to a no-exercise group, so we don't know how much better these exercises are than doing nothing.
- 05
Also, the exact amount of improvement (e.g., points on a pain scale) was not reported, so we can't say how meaningful the changes were in absolute terms.
Practical takeaways
If you have knee osteoarthritis, slow resistance training—either focusing on the lifting or lowering phase—may be a feasible supervised option for a 12-week program.
No control group, so we cannot say it is better than no exercise. No effect sizes or absolute improvements were reported. Small sample (n=56) and retrospective registration reduce confidence.
low confidenceDo not assume eccentric-only training is superior for knee osteoarthritis based on this trial.
No between-group difference is not evidence of equivalence. The study may have been underpowered to detect small differences.
low confidenceConsider a multimodal rehabilitation program that also includes cardiorespiratory endurance and joint range-of-motion work.
This is suggested by the authors but was not directly tested in this trial.
low confidenceWhy this study matters
Both slow lifting and slow lowering improved pain and function
In a 12-week randomized trial, 56 women with symptomatic knee osteoarthritis did supervised resistance training twice a week. Both the slow eccentric-only (lowering) and slow concentric-only (lifting) groups showed significant within-group improvements in WOMAC pain and physical function, muscle strength, knee extensor torque, fat-free mass, lower-limb muscle mass, and selected functional performance measures (all p<0.05). No effect sizes or absolute improvements were reported.
People with knee arthritis often wonder which exercise style is best. This suggests both slow lifting and slow lowering may be viable short-term options, though we can't say how much better they are than doing nothing.
No winner between eccentric-only and concentric-only
Despite comparing two distinct slow resistance-training modes, the trial found no significant between-group differences for any outcome. The authors caution that this should not be interpreted as formal evidence of equivalence between the two training modes.
It challenges the idea that one mode—often eccentric training—is clearly superior for knee osteoarthritis. But a null result in a small trial is not proof of equality.
The study cannot prove equivalence
The abstract states: 'The observed improvements primarily reflect within-group changes over time, and the results should not be interpreted as formal evidence of equivalence between the two training modes.' No effect sizes, confidence intervals, or absolute improvements were reported.
Many people hear 'no difference' and assume the treatments are equal. This is a classic research nuance: absence of evidence is not evidence of absence.
Small sample and retrospective registration
Only 56 women were randomized (28 per group), and the trial was registered retrospectively. The full paper was not available for this analysis, so methodology details cannot be verified.
These limitations affect confidence in the findings. Creators can use this as a teaching moment about study quality.
Feasibility and multimodal rehab
The authors conclude that both SET and SCT are feasible short-term supervised resistance-training options for middle-aged and older women with knee osteoarthritis. They also suggest that additional strategies targeting cardiorespiratory endurance and joint range of motion may be needed within a multimodal rehabilitation program.
This gives practical direction: resistance training may be one piece, but a complete program may need more.
Within-group improvements, no control group
The abstract reports significant within-group improvements, but there was no non-exercise control group. This means we cannot tell how much of the improvement was due to the training itself versus time, placebo, or regression to the mean.
It's a key reason why the findings are promising but not definitive.
Want the whole report?
Detailed mode opens the full scientific breakdown — every score component, the methodology, conflicts of interest, the evidence analysis behind each claim, and the raw study data.
Overview
What the study found
The study in plain English — the bottom line, every takeaway we extracted, and what to do with them.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Researchers tested two types of slow resistance training in older women with knee osteoarthritis. Both types helped reduce pain and improve function and strength over 12 weeks, but neither was clearly better than the other.
Research results
Both groups improved in pain, physical function, muscle strength, and muscle mass (p<0.05). No significant difference between groups. Effect sizes not reported.
What this means - more context
The study didn't compare to a no-exercise group, so we don't know how much better these exercises are than doing nothing. Also, the exact amount of improvement (e.g., points on a pain scale) was not reported, so we can't say how meaningful the changes were in absolute terms.
To compare the short-term effects of slow eccentric-only versus slow concentric-only resistance training on pain, physical function, muscle strength, muscle mass, and joint range of motion in middle-aged and older women with knee osteoarthritis.
In this 12-week randomized trial of 56 women with knee osteoarthritis, both slow eccentric-only and slow concentric-only resistance training led to significant within-group improvements in WOMAC pain and physical function, muscle strength, knee extensor torque, fat-free mass, lower-limb muscle mass, and selected functional performance measures (all p<0.05). No significant between-group differences were found. The authors caution that these results should not be interpreted as formal evidence of equivalence between the two training modes. Effect sizes and absolute improvements were not reported in the abstract.
Methods Used
Randomized, assessor-blinded trial. 56 women with symptomatic knee osteoarthritis were assigned to slow eccentric-only (n=28) or slow concentric-only (n=28) resistance training. Both groups completed a 12-week supervised program (2 sessions/week). Outcomes assessed at baseline and post-intervention using WOMAC index, muscle strength testing, body composition analysis, functional performance tests, and joint range-of-motion measurements. Trial retrospectively registered.
Main Finding
Both SET and SCT showed significant within-group improvements in pain, physical function, muscle strength, and muscle mass (p<0.05), with no significant between-group differences. No effect sizes, confidence intervals, or absolute improvements were reported. The authors state these findings should not be interpreted as formal evidence of equivalence.
Confidence Level
Limited - based on abstract only; full methodology not available. Small sample size (n=56), retrospective registration, and lack of reported effect sizes reduce confidence.
Study Flags
Red Flags
- •Small sample size (n=56)
- •Retrospectively registered
- •No effect sizes or confidence intervals reported in abstract
- •Full text not available - methodology details cannot be verified
No biological mechanisms were identified in this study. This may be an epidemiological, observational, or survey-based study that reports associations rather than proposing causal biological pathways.
Practical Takeaways
If you have knee osteoarthritis, slow resistance training—either focusing on the lifting or lowering phase—may be a feasible supervised option for a 12-week program.
RCT reviewsReviews of RCTs (Meta-analyses)
Max 100Randomized TrialsRandomized Trials
Max 90Reviews of Cohort StudiesReviews of Cohort Studies
Max 85Cohort StudiesCohort Studies
Max 72Reviews of Case-Control StudiesReviews of Case-Control Studies
Max 63Case-Control StudiesCase-Control Studies
Max 58Cross-Sectional & Case SeriesCross-Sectional & Case Series
Max 50Expert OpinionExpert Opinion
Max 545 / 100
Probability of being correct
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Human RCT
Subject
Moderate probability
on the GRADE evidence scale
This study randomly put women into two exercise groups and checked if they felt better after 12 weeks. Both groups improved, but there was no group that didn't exercise, so we can't tell if the exercise caused the improvement or if it would have happened anyway. It also doesn't prove that one exercise is as good as the other.
Strengths
- Randomized allocation
- Assessor-blinded outcome assessment
- Supervised 12-week resistance training program
Weaknesses
- No non-exercise control group
- Small sample size
- No significant between-group differences; underpowered for equivalence
Methodology
Evidence Keywords
Statistical Reporting
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Researchers tested two types of slow resistance training in older women with knee osteoarthritis. Both types helped reduce pain and improve function and strength over 12 weeks, but neither was clearly better than the other.
Research results
Both groups improved in pain, physical function, muscle strength, and muscle mass (p<0.05). No significant difference between groups. Effect sizes not reported.
What this means - more context
The study didn't compare to a no-exercise group, so we don't know how much better these exercises are than doing nothing. Also, the exact amount of improvement (e.g., points on a pain scale) was not reported, so we can't say how meaningful the changes were in absolute terms.
To compare the short-term effects of slow eccentric-only versus slow concentric-only resistance training on pain, physical function, muscle strength, muscle mass, and joint range of motion in middle-aged and older women with knee osteoarthritis.
In this 12-week randomized trial of 56 women with knee osteoarthritis, both slow eccentric-only and slow concentric-only resistance training led to significant within-group improvements in WOMAC pain and physical function, muscle strength, knee extensor torque, fat-free mass, lower-limb muscle mass, and selected functional performance measures (all p<0.05). No significant between-group differences were found. The authors caution that these results should not be interpreted as formal evidence of equivalence between the two training modes. Effect sizes and absolute improvements were not reported in the abstract.
Methods Used
Randomized, assessor-blinded trial. 56 women with symptomatic knee osteoarthritis were assigned to slow eccentric-only (n=28) or slow concentric-only (n=28) resistance training. Both groups completed a 12-week supervised program (2 sessions/week). Outcomes assessed at baseline and post-intervention using WOMAC index, muscle strength testing, body composition analysis, functional performance tests, and joint range-of-motion measurements. Trial retrospectively registered.
Main Finding
Both SET and SCT showed significant within-group improvements in pain, physical function, muscle strength, and muscle mass (p<0.05), with no significant between-group differences. No effect sizes, confidence intervals, or absolute improvements were reported. The authors state these findings should not be interpreted as formal evidence of equivalence.
Confidence Level
Limited - based on abstract only; full methodology not available. Small sample size (n=56), retrospective registration, and lack of reported effect sizes reduce confidence.
Study Flags
Red Flags
- •Small sample size (n=56)
- •Retrospectively registered
- •No effect sizes or confidence intervals reported in abstract
- •Full text not available - methodology details cannot be verified
No biological mechanisms were identified in this study. This may be an epidemiological, observational, or survey-based study that reports associations rather than proposing causal biological pathways.
Practical Takeaways
If you have knee osteoarthritis, slow resistance training—either focusing on the lifting or lowering phase—may be a feasible supervised option for a 12-week program.
RCT reviewsReviews of RCTs (Meta-analyses)
Max 100Randomized TrialsRandomized Trials
Max 90Reviews of Cohort StudiesReviews of Cohort Studies
Max 85Cohort StudiesCohort Studies
Max 72Reviews of Case-Control StudiesReviews of Case-Control Studies
Max 63Case-Control StudiesCase-Control Studies
Max 58Cross-Sectional & Case SeriesCross-Sectional & Case Series
Max 50Expert OpinionExpert Opinion
Max 545 / 100
Probability of being correct
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Human RCT
Subject
Moderate probability
on the GRADE evidence scale
This study randomly put women into two exercise groups and checked if they felt better after 12 weeks. Both groups improved, but there was no group that didn't exercise, so we can't tell if the exercise caused the improvement or if it would have happened anyway. It also doesn't prove that one exercise is as good as the other.
Strengths
- Randomized allocation
- Assessor-blinded outcome assessment
- Supervised 12-week resistance training program
Weaknesses
- No non-exercise control group
- Small sample size
- No significant between-group differences; underpowered for equivalence
Methodology
Evidence Keywords
Statistical Reporting
Scoring
How strong is this study?
The study did some things well, like randomly assigning people and having the person measuring results not know which group they were in. But it was small and had no control group, so the results are not strong enough to say the exercises definitely work. We also only have a short summary, not the full details.
0 / 100
- COI disclosureconflicts of interest not disclosed
- Data availabilitydata not shared
- Code availabilitycode not shared
55 / 100
- Randomization+20/20
- Blinding+9/15
- Control groupno control group
- Sample size (n=56)+4.9/20
- Follow-up+10/10
100 / 100
23 / 100
- P-values+15/15
- Effect sizeno effect size reported
- Confidence intervalsno confidence intervals
- Pre-registrationnot pre-registered
Each component is scored out of 100 and then capped by the study design — a case series cannot reach the ceiling a randomised trial can, however well it is reported.
Where it sits
RCT reviewsReviews of RCTs (Meta-analyses)
Max 100Randomized TrialsRandomized Trials
Max 90Reviews of Cohort StudiesReviews of Cohort Studies
Max 85Cohort StudiesCohort Studies
Max 72Reviews of Case-Control StudiesReviews of Case-Control Studies
Max 63Case-Control StudiesCase-Control Studies
Max 58Cross-Sectional & Case SeriesCross-Sectional & Case Series
Max 50Expert OpinionExpert Opinion
Max 545 / 100
Probability of being correct
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
This design cannot establish causation — the findings describe an association, not a cause. No non-exercise control group; within-group improvements cannot be attributed to the intervention. No significant between-group differences were detected, and the trial is underpowered for equivalence. Abstract-only report limits verification of methodology.
COI Unknown
Could not determine conflict of interest status
No conflict of interest or funding statement was provided in the abstract; COI status and funding sources cannot be determined.
Abstract only; no COI or funding section. Trial was retrospectively registered (UMIN000060649), which is a separate transparency concern but not a COI. No author affiliations are provided.
Standing
The people behind it
The researchers who wrote the study this analysis is built on.
Authored by
6 researchersIf this is your work, this is how we attribute it on Fit Body Science. Ping Liu is listed as the lead author.