Triceps Brachii Muscle Strength and Architectural Adaptations with

The aim of this study was to investigate whether resistance training at short or long triceps
brachii fascicle length induces different muscular strength and architectural adaptations. Nine young,
novice, female participants, were trained for 6 weeks (two sessions/week) performing 6 sets6-RM
(repetition maximum) unilateral cable exercises either with push-downs at short fascicle length (S) or
overhead extensions with the contralateral arm at long fascicle length (L) of triceps brachii. Before and
after training, 1-RM elbow extension and triceps brachii muscle architecture were evaluated. Muscle
architecture was analyzed at 50% and 60% of the upper-arm length. Two-dimensional longitudinal
muscle area of the triceps long head was also analyzed.
These results indicate that muscle strength and architecture of elbow extensors adapt similarly during
the first six weeks of resistance training at either long or short fascicle length.
Keywords:long head of triceps brachii; panoramic ultrasound imaging; fascicle length1. Introduction
Resistance training is popular among training enthusiasts for increasing muscular strength and
mass. Exposure to chronic resistance training induces muscle hypertrophy as well as significant health
benefits both for female and male participants [1]. However, compared to males, females have lower
muscle mass and therefore lower muscle strength [2]. This difference is even more pronounced for the
upper body where the difference may be as large as 50% [2]. This suggests that resistance training for
the upper body musculature is important for females.
Different resistance exercises have been proposed for the upper body musculature. Some of these
exercises force the protagonist muscles to work at extended lengths while others at short lengths.
Nevertheless, little is known about the effectiveness of each one of these different training positions to
promote muscle mass and hypertrophy. It has been proposed that resistance exercise at different muscle
lengths may force muscles to work at various areas of the length-tension curve [3]. For example, two of
the most popular resistance exercises for strengthening the elbow extensors are the cable push-downs
J. Funct. Morphol. Kinesiol.2018,3, 28; doi:10.3390/jfmk3020028www .mdpi.com/journal/jfmk
J. Funct. Morphol. Kinesiol.2018,3, 282 of 10and the cable overhead extension performed with a pulley. The long head of the triceps brachii, one of