Mixed-Nerve Silent Period Characteristics During Muscle Output Regulation in Healthy Athletes: Preliminary Findings and Comparison with a Single Postoperative Case.
Shinichi Daikuya, Yumi Okayama
PMID 42549197WHAT IT FOUND
One athlete three months after meniscal repair showed a prolonged neural response indicating altered brain excitability on the injured side versus healthy teammates, suggesting her delayed return to running may involve central changes that standard strength and range-of-motion tests miss.
Key findings
01In the healthy athletes, the mixed-nerve silent period was 106.3 ± 7.5 ms on the dominant leg and 103.2 ± 6.5 ms on the nondominant leg, with no significant difference between sides (p = 0.12).
02The postoperative athlete's injured (dominant) leg showed a silent period of 123.7 ms, deviating by more than 2 standard deviations from the healthy reference and reaching statistical significance (p = 0.045, effect size Z-CC = 2.320).
03The athlete's non-injured (nondominant) leg showed a silent period of 110.8 ms, which did not differ from the healthy reference group.
STILL TO COME
How it was doneWhat they foundWhat it means for PTs
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What it does not show
The main comparison rests on a single postoperative athlete; the authors themselves state the findings are hypothesis-generating rather than confirmatory. The healthy reference group is small (13 participants, close to the minimum required by power analysis) and drawn from a single basketball team, limiting generalisability to other sports or populations. No longitudinal follow-up of the postoperative athlete was performed, so it is unknown whether the prolonged silent period resolved with continued rehabilitation. The test-retest reliability of the silent period measure has not been established in this or prior work cited by the authors. The silent period was recorded from the upper limb (hand) during a lower-limb task, so it reflects generalised central excitability rather than a local measure of the injured knee.
Declared interests
The authors report no conflicts of interest.
The easy way to misread this
Do not read the prolonged silent period in this one athlete as evidence that SP testing should be added to return-to-sport protocols. This is a single case compared to 13 teammates from the same team, the authors explicitly label the finding hypothesis-generating, the test-retest reliability of the measure is unestablished, and the equipment required (TMS/EMG setup) is not available in most outpatient clinics.