Ultrasound and surface electromyography analyses reveal an intensity dependent active stretch‐shortening cycle of the vastus lateralis muscle during ergometer rowing

Abstract

A rowing cycle is characterised by a stretch-shortening cycle (SSC) at the quadriceps femoris muscle-tendon unit (MTU) level. However, due to the associated decoupling between MTU and muscle fascicle length changes, it remains unclear whether a rowing cycle causes active stretch at the muscle level. Fifteen young, sub-elite, male rowers (19.5 ± 1.6 yr; 1.94 ± 0.06 m; 91.9 ± 5.4 kg; rowing experience: 7.5 ± 2.8 yr) performed randomised 60-s rowing intervals using a traditional style at a low (LiR) and high intensity (HiR) and a micro-pause style at a low intensity (MpR). Muscle activity, knee joint angles, and muscle fascicle length changes from the left-sided vastus lateralis (VL) muscle were quantified using surface electromyography, inertial measurement units, and B-mode ultrasound imaging, respectively. All rowing conditions showed active fascicle stretch during late knee flexion (p≤0.001, standardised mean difference (SMD) ≥0.72) and subsequent active fascicle shortening throughout knee extension. Active fascicle stretch duration, amplitude and velocity (rANOVA: p≤0.001, η p 2 = 0.49) were not significantly different (p≥0.174; SMD≤0.26) between LiR and MpR, but were significantly increased during HiR (p≤0.001; SMD≥0.70). The percentage of rowing cycles that involved active fascicle stretch (rANOVA: p≤0.001, η p 2 = 0.95; post-hoc: p≤0.001, SMD≥0.87) was also significantly higher for HiR (98.3 ±12.9%) compared with both LiR (65.0 ± 48.1%) and MpR (68.3 ± 46.9%). In conclusion, rowing involves SSC at the VL muscle fascicle level, but the amount of active stretch differs between rowing intensities, with the longest, largest, and fastest active stretch occurring during HiR. SSC-based mechanisms may therefore contribute more to rowing performance during HiR than LiR or MpR. Highlights. Surface electromyography and ultrasound imaging revealed stretch-shortening cycles (SSCs) of the vastus lateralis muscle fascicles during rowing . Increased active fascicle stretch duration, amplitude and velocity from low-to high-intensity rowing indicate that SSC-based mechanisms likely contribute more to performance during high-intensity rowing . The SSC within the vastus lateralis muscle was independent of the rowing style at the same low rowing intensity

Acute effects of muscle mechanical properties after 2000-m rowing in young male rowers

“…Rowing, which involves repetitive muscular motion, is a highly physiologically demanding competitive sport. Each rowing cycle is characterized by a stretching–shortening cycle (SSC) at the muscle–tendon unit ( Held et al, 2022 ). Muscle tone and stiffness have been shown to affect the effectiveness of SSCs ( Ishikawa et al, 2006 ; De Ste Croix et al, 2021 ).…”

A Conceptual Exploration of Hamstring Muscle–Tendon Functioning during the Late-Swing Phase of Sprinting: The Importance of Evidence-Based Hamstring Training Frameworks

“…Considering the widespread applications of eccentric muscle functioning, it is perhaps unsurprising that eccentric muscle behaviour can commonly be observed in humans in a variety of muscles and during a range of spring-driven and motor-driven locomotive activities requiring force production, energy absorption and/or utilisation of the stretch–shorten cycle. This includes but is not limited to loaded exercises involving controlled lengthening contractions of the hamstrings, such as the Nordic hamstring curl [ 141 – 143 ], single-leg Roman chair [ 141 ], and single-leg deadlift [ 141 ], loaded exercises involving lengthening contractions of the tibialis anterior [ 138 ], gastrocnemius and soleus [ 144 – 147 ], and the vastus lateralis and vastus intermedius muscles [ 148 , 149 ], downhill running [ 150 ], eccentric cycling [ 151 ], rowing [ 152 ], and countermovement and drop jumps [ 153 – 155 ]. As already noted, small fascicle stretches have also been observed in the triceps surae during the spring-driven activities of walking [ 88 , 89 ], running [ 70 , 89 ], sprinting [ 127 ] and submaximal hopping [ 90 , 128 ].…”

“…During certain locomotive tasks, the degree of fascicle stretching that presents also appears to share a relationship with intensity. For example, it has been demonstrated that the duration, amplitude and velocity of active fascicle stretches increase in the vastus lateralis with heightened rowing intensities [ 152 ]. Similarly, drop jumps from relatively high heights result in sudden stretches of the muscle fascicles located in the triceps surae [ 153 , 154 ].…”

Muscle function during locomotion on skis at varying speed and incline conditions

“…However, this energy efficient contraction mode is not apparent in all locomotor activities. Recent studies examining muscle behaviour during race walking and rowing, showed that fascicles followed the stretch-shortening cycle of the MTU, resulting in less efficient contractile patterns (Cronin et al, 2016; Held et al, 2022).…”