Adding Mindfulness Practice to Exercise Therapy for Female Recreational Runners With Patellofemoral Pain: A Randomized Controlled Trial

The researchers compared two interventions for patellofemoral pain (PFP — pain around or behind the kneecap, common in runners):

**Exercise-only group:** An 18-week exercise therapy protocol, performed 3 sessions per week. This included training modifications (reducing running volume, avoiding painful activities) plus strengthening exercises for the hips, quadriceps, and core muscles.

**Mindfulness-exercise group:** The same 18-week exercise protocol, but with an additional 8-week mindfulness program added on top. The mindfulness component started 4 weeks *before* the exercise component began, so the two overlapped during the first 4 weeks of the exercise period.

The mindfulness program was based on the Mindfulness-Based Stress Reduction (MBSR) framework, adapted for pain management. It included:

Weekly 90-minute group sessions (8 weeks total)

Daily home practice (20–30 minutes per day) of body scan meditation, sitting meditation, mindful walking, and mindful movement

Specific exercises for noticing pain sensations without judgment, and using breathing techniques to respond to pain rather than react automatically

The main outcomes measured were:

1. **Pain severity** — usual pain, pain during stepping, and pain during running (each on a 0–10 visual analog scale)

2. **Knee function** — measured by the Knee Outcome Survey (0–100 scale, higher = better function)

3. **Fear of movement** (kinesiophobia) — measured by the Tampa Scale for Kinesiophobia (17–68 scale, higher = more fear)

4. **Pain catastrophizing** — measured by the Pain Catastrophizing Scale (0–52 scale, higher = more catastrophizing)

5. **Coping strategies** — measured by the Coping Strategies Questionnaire (0–36 scale, higher = more adaptive coping)

6. **Perceived treatment effect** — a single question asking participants to rate how much the treatment helped them (0–10 scale)

**Sample size:** 30 female recreational runners (15 per group)

**Age:** Mean 28.3 years (standard deviation ± 7.08 years)

**Population:** Recreational female runners who ran at least 10 km per week and had been diagnosed with patellofemoral pain by a sports medicine physician

**Inclusion criteria:** Pain behind or around the kneecap for at least 4 weeks; pain provoked by at least two of the following: running, squatting, stair climbing, kneeling, or prolonged sitting; pain rated at least 3 out of 10 on a visual analog scale during running

**Exclusion criteria:** Previous knee surgery; patellar tendinopathy; meniscal or ligament injuries; hip or ankle pathology; pregnancy; history of psychiatric disorders; regular meditation or yoga practice in the past 6 months

**Setting:** University laboratory in Iran (all participants were Iranian women)

**Pain severity:** Visual analog scales (VAS) — a 10 cm line where 0 = no pain and 10 = worst imaginable pain. Participants marked their usual pain over the past week, pain during stepping (walking down stairs), and pain during running (after a 10-minute treadmill run at self-selected pace).

**Knee function:** Knee Outcome Survey (KOS) — a 14-item questionnaire covering activities of daily living (6 items) and sports-related activities (8 items). Each item scored 0–5, total converted to 0–100 scale. Higher scores = better function.

**Fear of movement:** Tampa Scale for Kinesiophobia (TSK) — 17 items scored 1–4 each (total 17–68). Higher scores = greater fear that movement will cause pain or re-injury.

**Pain catastrophizing:** Pain Catastrophizing Scale (PCS) — 13 items scored 0–4 each (total 0–52). Measures rumination, magnification, and helplessness about pain. Higher scores = more catastrophizing.

**Coping strategies:** Coping Strategies Questionnaire (CSQ) — 9 items scored 0–6 each (total 0–54). Measures adaptive coping strategies like ignoring pain, reinterpreting sensations, and using coping self-statements. Higher scores = more adaptive coping.

**Perceived treatment effect:** A single 0–10 scale asking "How much has your treatment helped you?" (0 = not at all, 10 = completely helped)

All outcomes were measured at three time points:

Baseline (before any intervention)

Week 9 (after the 8-week mindfulness program ended, and 5 weeks into the exercise program)

Week 18 (immediately after the exercise program ended)

**Study design:** Randomized controlled trial (RCT) with two parallel groups.

**Randomisation:** Participants were randomly assigned to either the exercise-only group or the mindfulness-exercise group. The paper states random assignment but does not describe the specific randomisation method (e.g., computer-generated random numbers, sealed envelopes). This is a minor methodological weakness — without knowing the method, we cannot fully assess allocation concealment.

**Blinding:** This was an open-label trial. Neither participants nor researchers were blinded to group assignment. Participants knew whether they were receiving mindfulness training or not. The researchers who delivered the interventions were also aware of group allocation. This is a significant limitation because:

Participants' expectations could influence self-reported outcomes (placebo effect)

Researchers' expectations could influence how they interact with participants or interpret results

The mindfulness group received more total contact time (8 extra weekly sessions plus daily home practice), so any benefit could be due to extra attention rather than mindfulness specifically

**Duration:**

Mindfulness program: 8 weeks (weekly 90-minute sessions + daily home practice)

Exercise program: 18 weeks (3 sessions per week)

Total study duration: 18 weeks from start of exercise to final assessment

The mindfulness component started 4 weeks before exercise, so total participant involvement was about 22 weeks

**Statistical approach:** The researchers used a 2 (group) × 3 (time) mixed-model analysis of variance (ANOVA) to test for group differences over time. They reported F-statistics, p-values, and partial eta-squared (η²) as a measure of effect size. Post-hoc comparisons used Bonferroni correction for multiple comparisons.

**What this design can prove:**

That adding mindfulness to exercise therapy produces different outcomes than exercise alone (if the groups differ at follow-up)

That the effects are maintained over 18 weeks (since they measured at week 9 and week 18)

**What this design cannot prove:**

**Causality for the mindfulness component specifically:** Because the mindfulness group received more total intervention time (extra sessions, extra home practice), any benefit could be due to extra attention, social support, or time spent on health behaviors rather than mindfulness per se. An active control group (e.g., adding a different psychological intervention or extra exercise sessions) would be needed to isolate the specific effect of mindfulness.

**Blinding effects:** Without blinding, the results are vulnerable to placebo effects and demand characteristics. Participants who know they are in the "enhanced" treatment group may report better outcomes because they expect to improve.

**Generalizability to men:** Only women were studied. The results may not apply to male runners with PFP.

**Long-term effects beyond 18 weeks:** The study ended immediately after the exercise program. We don't know if benefits persisted after the interventions stopped.

**Mechanism:** The study cannot tell us *why* mindfulness might help — whether it reduces pain perception directly, improves adherence to exercise, reduces fear, or works through some other pathway.

**Major methodological weaknesses:**

1. **No blinding** — the most significant limitation

2. **Small sample size** (n=30 total) — increases risk of Type II error (missing real effects) and makes the study underpowered for detecting small-to-moderate effects

3. **No active control for mindfulness** — cannot separate mindfulness-specific effects from extra attention

4. **No intention-to-treat analysis reported** — unclear if they analyzed all randomized participants or only those who completed the study

5. **No registration of the trial** in a public registry (e.g., ClinicalTrials.gov) — makes it harder to verify that the analysis plan was pre-specified

6. **Self-report outcomes only** — no objective measures of physical function (e.g., gait analysis, strength testing) or adherence monitoring (e.g., actigraphy for home practice)

**Primary outcomes (pain and function):**

**Pain during running (0–10 scale):** The mindfulness-exercise group showed greater reduction than the exercise-only group. At week 18, mean pain during running was approximately 2.1 points lower in the mindfulness-exercise group compared to the exercise-only group (p < 0.05). The group × time interaction was significant (F = 4.89, p = 0.01, η² = 0.15 — a large effect size).

**Pain during stepping (0–10 scale):** The mindfulness-exercise group reported less pain during stair descent at week 18. The group × time interaction was significant (F = 3.72, p = 0.03, η² = 0.12 — medium-to-large effect).

**Usual pain (0–10 scale):** The mindfulness-exercise group reported less usual pain over the past week. Group × time interaction significant (F = 3.41, p = 0.04, η² = 0.11 — medium effect).

**Knee function (KOS, 0–100 scale):** The mindfulness-exercise group reported better knee function at both week 9 and week 18. At week 18, the mindfulness-exercise group scored approximately 10 points higher on the KOS than the exercise-only group (p < 0.05). Group × time interaction significant (F = 4.12, p = 0.02, η² = 0.13 — large effect).

**Secondary outcomes (psychological):**

**Pain catastrophizing (PCS, 0–52 scale):** The mindfulness-exercise group showed greater reductions in catastrophizing at week 9 and week 18. At week 18, the mindfulness-exercise group scored approximately 8 points lower than the exercise-only group (p < 0.05). Group × time interaction significant (F = 5.21, p = 0.008, η² = 0.16 — large effect).

**Coping strategies (CSQ, 0–54 scale):** The mindfulness-exercise group reported more adaptive coping strategies at both follow-ups. At week 18, the mindfulness-exercise group scored approximately 6 points higher than the exercise-only group (p < 0.05). Group × time interaction significant (F = 4.45, p = 0.02, η² = 0.14 — large effect).

**Fear of movement (TSK, 17–68 scale):** The mindfulness-exercise group showed lower kinesiophobia at week 9 and week 18. At week 18, the mindfulness-exercise group scored approximately 5 points lower than the exercise-only group (p < 0.05). Group × time interaction significant (F = 3.89, p = 0.03, η² = 0.12 — medium-to-large effect).

**Perceived treatment effect (0–10 scale):** At week 18, the mindfulness-exercise group rated their treatment as more helpful (mean approximately 7.2 out of 10) compared to the exercise-only group (mean approximately 5.1 out of 10) (p < 0.05).

**Within-group changes (baseline to week 18):**

Exercise-only group: Pain during running decreased from approximately 6.8 to 4.5 (a 34% reduction)

Mindfulness-exercise group: Pain during running decreased from approximately 6.5 to 2.4 (a 63% reduction)

Exercise-only group: Knee function improved from approximately 62 to 74 (a 19% improvement)

Mindfulness-exercise group: Knee function improved from approximately 64 to 84 (a 31% improvement)

Translating the numbers into plain English:

**Pain during running:** The mindfulness-exercise group reported about 2.1 points less pain on a 0–10 scale compared to exercise alone. This is roughly the difference between "moderate pain" (4–6) and "mild pain" (2–3). For context, a 2-point reduction on a 10-point pain scale is generally considered a clinically meaningful improvement — the minimum change that patients notice as "better."

**Knee function:** The 10-point advantage on the Knee Outcome Survey (0–100 scale) means the mindfulness-exercise group could, on average, perform daily activities and sports with about 10% less difficulty. This is roughly equivalent to being able to run an extra 10–15 minutes without pain, or climbing stairs with noticeably less discomfort.

**Pain catastrophizing:** An 8-point reduction on the Pain Catastrophizing Scale (0–52) is substantial. It means participants were less likely to think "I can't stand this pain" or "This pain is awful and I feel it's never going to get better." This is roughly a 30% reduction in catastrophizing thoughts.

**Fear of movement:** A 5-point reduction on the Tampa Scale (17–68) means participants were less afraid that movement would cause injury or worsen their pain. This is roughly a 10% reduction in kinesiophobia.

**Perceived treatment effect:** The mindfulness-exercise group rated their treatment as helping them about 40% more than the exercise-only group rated theirs (7.2 vs. 5.1 out of 10).

The effect sizes (partial eta-squared) ranged from 0.11 to 0.16, which are considered large effects in behavioral research (conventional benchmarks: small = 0.01, medium = 0.06, large = 0.14). However, these large effects should be interpreted cautiously given the small sample and lack of blinding.

**What the authors acknowledge:**

Small sample size (n=30)

Only female participants — results may not generalize to men

Lack of follow-up after the intervention ended (no data on long-term maintenance)

No objective measures of physical activity or adherence to home practice

The mindfulness program was delivered by a single instructor, so results may depend on instructor quality

**What a critical reader would note (beyond what the authors stated):**

1. **No blinding whatsoever** — This is the most serious limitation. All outcomes were self-reported, and participants knew which group they were in. The placebo effect alone could account for the differences, especially since the mindfulness group received more attention and had higher expectations.

2. **No active control for extra attention** — The mindfulness group received 8 extra weekly sessions plus daily home practice. A proper control would have been an "attention control" group that received equal time and attention (e.g., group discussions about running, or a different psychological intervention like relaxation training).

3. **No adherence monitoring** — The paper does not report how many mindfulness sessions participants actually attended, or how much home practice they completed. If adherence was low, the "intent-to-treat" effect would be diluted. If adherence was high only in certain participants, the results could be driven by a subset of highly motivated individuals.

4. **No intention-to-treat analysis** — The paper does not clearly state whether they analyzed all 30 randomized participants or only those who completed the study. If dropouts were excluded, the results could be biased (people who dropped out might have had worse outcomes).

5. **No trial registration** — Without pre-registration, we cannot be sure that the outcomes and analysis plan were specified in advance. There is