Thygesen MM, Jordt I, Kristensen MS, Fisker FY, Kildegaard S, Pfeiffer-Jensen M. High-Intensity Resistance Training Does Not Produce Immediate Ultrasonographic Changes in Muscle Tendons.
Orthop J Sports Med 2019;
7:2325967118821604. [PMID:
30729146 PMCID:
PMC6350153 DOI:
10.1177/2325967118821604]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Background:
Chronic overload injuries to tendons can be visualized using ultrasonography,
with characteristics such as tendon thickening and darkening.
Purpose:
To investigate whether these characteristics are evident in the patellar and
Achilles tendons immediately after 1 session of high-intensity resistance
training.
Study Design:
Controlled laboratory study.
Methods:
A total of 18 volunteers were randomized to an experimental group (n = 10)
and a sham group (n = 8). The experimental group performed 5 circuits at
maximum effort consisting of 5 weighted front squats, 10 box jumps (60/50
cm), and 15 double-under jump-rope jumps. The sham group performed a similar
circuit consisting of 5 weighted shoulder presses, 10 push-ups, and 15
weighted biceps curls. Ultrasonograms were obtained before and after
exercise, for a total of 30 minutes at intervals of 2.5 minutes for the
first 10 minutes and 5 minutes for the remaining time. Tendon thickness and
tendon matrix signals were measured. Statistics were performed using
repeated-measures mixed analysis of variance (ANOVA).
Results:
Tendon thickness did not increase significantly over 30 minutes after both
circuits. The mean grayscale value for the patellar and Achilles tendons
increased for both the experimental and the sham groups. ANOVA showed that
the experimental group was not a significant explanatory variable; however,
the increased work of both groups was. A post hoc analysis found that the
maximum increase in the tendon signal was a grayscale value of 10.8 for the
patellar tendon (99.4% CI, 3.7-17.9; P = .002).
Conclusion:
This trial failed to reproduce an earlier study in which tendon thickness
increased after high-intensity training. The tendons produced a hyperechoic
signal after high-intensity resistance training, regardless of loading to
the tendon. Chronic overload characteristics on ultrasonography were not
evident immediately after acute loading of tendons.
Clinical Relevance:
There is a need for prognostic and diagnostic markers of tendinopathy
especially because of the protracted course of subclinical development of an
injury. This study assessed whether clinical findings for a chronic overload
injury can be detected during acute overloading.
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