Effects of the Functional Heel Drop Exercise on the Muscle Architecture of the Gastrocnemius

Abstract

Context: The architectural characteristics of a muscle determine its function. Objective: To determine the architectural adaptations of the lateral gastrocnemius (LG) and medial gastrocnemius (MG) muscles after a functional eccentric strength training protocol consisting of heel drop exercises, followed by a subsequent detraining period. Design: Pretest and posttest. Setting: Training rooms and laboratory. Participants: The participants (N = 45) who were randomly divided into an experimental group (EG, n = 25) and a control group (CG, n = 20). Interventions: The 13-week intervention included participants (N = 45) who were randomly divided into an EG (n = 25) and a CG (n = 20). The EG performed a week of control and training, 8 weeks of eccentric training, and 4 weeks of detraining. The CG did not perform any type of muscular training. The architectural characteristics of the LG and MG muscles were evaluated at rest in both groups using 2-D ultrasound before (pretest–week 1) and after (posttest–week 9) the training, and at the end of the detraining period (retest–week 13). Main Outcome Measures: One-way repeated measures analysis of variance was used to determine training-induced changes in each of the variables of the muscle architecture. Results: After the training period, the members of the EG experienced a significant increase in the fascicle length of LG (t = −9.85, d = 2.78, P < .001) and MG (t = −8.98, d = 2.54, P < .001), muscle thickness (t = −6.71, d = 2.86, P < .001) and (t = −7.85, d = 2.22, P < .001), and the pennation angle (t = −10.21, d = 1.88, P < .05) and (t = −1.87, d = 0.53, P < .05), respectively. After the detraining period, fascicle length, muscle thickness, and pennation angle showed a significant decrease. In the CG, no significant changes were observed in any of the variables. Conclusions: The heel drop exercise seems to generate adaptations in the architectural conditions of LG and MG, which are also reversible after a detraining period. These results may have practical implications for injury prevention and rehabilitation programs.

Effects of Copenhagen Adduction Exercise on Muscle Architecture and Adductor Flexibility

“…Different studies have analysed architectural changes in lower limb muscles after performing protocols based on eccentric exercises [ 15 , 17 , 18 , 19 , 21 , 22 ], but there is only one precedent work that has studied the architectural effects of CAE on the adductor muscle architecture. Alonso-Calvete et al [ 25 ] also obtained a significant increase in MT in the adductor longus after 8 weeks of CAE in young football players, but they could not discern whether these changes were derived solely from this intervention or from its combination with the training that the experimental subjects also performed as part of their sport.…”

“…Muscle thickness (MT) has previously been assessed with this method in hamstrings [ 17 , 20 ], quadriceps [ 16 , 22 ], the gastrocnemius muscle [ 21 ], and recently in adductors [ 25 ]. Thus, MT was determined in AL from ultrasound images obtained along the longitudinal axis of the muscle belly of the dominant limb using a B-mode ultrasound scanner (frequency = 12 MHz; depth = 8 cm; field of view = 14 × 47 mm) (GE Healthcare Vivid-i, Wauwatosa, WI, USA).…”

“…All the images were performed by the same experienced ultrasound technician [ 17 , 18 , 21 , 22 ], and shielded from the identity of the participants during the entire analysis.…”

“…The changes in muscle architecture produced by eccentric exercises have been verified using ultrasound imaging in different muscles of the lower limbs, such as the quadriceps femoris [ 15 , 16 ], hamstrings [ 17 , 18 , 19 , 20 ] and the gastrocnemius [ 21 ], highlighting the ability of ultrasound imaging to identify the structural changes in muscles following periods of training.…”

“…Different eccentric exercises that only use the athlete’s body weight have shown their importance in the modification of muscle morphology after the preventive exercise programme. For example, in hamstring strength training, the benefits of the Nordic hamstring exercise on the semitendinosus [ 17 ] and on the biceps femoris [ 18 ], the reverse Nordic exercise on the rectus anterior [ 22 ], and the heel drop on the gastrocnemius muscles [ 21 ] have all been proven.…”