Does a secondary cognitive task affect knee force production sense in young male soccer players

Key points

1. 01Knee force production sense error rose under a dual-task (mental countdown) compared with a single-task condition in both legs.
2. 02The effect was statistically significant for the dominant and nondominant knee.
3. 03Worse force sense under cognitive load may matter because poor proprioception is linked to higher knee injury risk.
4. 04Authors suggest training that combines motor and cognitive load could help, but this was an exploratory first study.

How it was conducted

Design

Within-subjects comparison, each player tested under single-task then dual-task conditions

Participants

24 young male licensed soccer players, ages 16 to 19 years

Task

Reproducing 50% of maximum voluntary quadriceps contraction with eyes closed, using a pressure biofeedback device; dual-task added counting down from 200 by fives

Outcome

Knee force production sense error (KFPSE), the absolute difference from the 50% MVC target, averaged over three trials per knee

Analysis

Paired Student t-test comparing single-task and dual-task conditions, p<0.05 significant

What they found

• Dominant knee KFPSE was higher under dual-task, 11.71 +/- 5.18 mm Hg, versus single-task, 7.87 +/- 4.02 mm Hg, t = -4.10, p < 0.001.
• Nondominant knee KFPSE was higher under dual-task, 11.71 +/- 6.75 mm Hg, versus single-task, 8.31 +/- 3.83 mm Hg, t = -2.81, p = 0.010.
• Higher deviation scores indicate poorer force production sense, so the dual-task condition produced worse accuracy in both legs.

Limitations

• Small single-group study of 24 players with no control group, so results are exploratory.
• Only young male soccer players were included, limiting how broadly the findings generalize to women, other ages, or expert players.
• The single-task condition was always tested before the dual-task condition, so task order was not randomized.
• Only one type of cognitive task was tested, so effects of other or harder tasks are unknown.

Why it matters

For patients

If you play soccer, distractions or split attention may temporarily reduce how well you sense and control force at the knee, which could affect movement quality.

For clinicians

Cognitive load can degrade knee force sense in young athletes, so dual-task screening and training may be worth considering in injury-prevention programs.

For readers

This early study suggests adding a mental task while measuring knee force sense increases error, hinting at a link between attention and proprioceptive control.