Daniel D. Hodgson

Bio: Daniel D. Hodgson is an academic researcher from Memorial University of Newfoundland. The author has contributed to research in topics: Electromyography & Isometric exercise. The author has an hindex of 7, co-authored 9 publications receiving 280 citations.

Effectiveness of Traditional Strength vs. Power Training on Muscle Strength, Power and Speed with Youth: A Systematic Review and Meta-Analysis

Abstract: Numerous national associations and multiple reviews have documented the safety and efficacy of strength training for children and adolescents. The literature highlights the significant training-induced increases in strength associated with youth strength training. However, the effectiveness of youth strength training programs to improve power measures is not as clear. This discrepancy may be related to training and testing specificity. Most prior youth strength training programs emphasized lower intensity resistance with relatively slow movements. Since power activities typically involve higher intensity, explosive-like contractions with higher angular velocities (e.g., plyometrics), there is a conflict between the training medium and testing measures. This meta-analysis compared strength (e.g., training with resistance or body mass) and power training programs (e.g., plyometric training) on proxies of muscle strength, power, and speed. A systematic literature search using a Boolean Search Strategy was conducted in the electronic databases PubMed, SPORT Discus, Web of Science, and Google Scholar and revealed 652 hits. After perusal of title, abstract, and full text, 128 studies were eligible for inclusion in this systematic review and meta-analysis. The meta-analysis showed small to moderate magnitude changes for training specificity with jump measures. In other words, power training was more effective than strength training for improving youth jump height. For sprint measures, strength training was more effective than power training with youth. Furthermore, strength training exhibited consistently large magnitude changes to lower body strength measures, which contrasted with the generally trivial, small and moderate magnitude training improvements of power training upon lower body strength, sprint and jump measures, respectively. Maturity related inadequacies in eccentric strength and balance might influence the lack of training specificity with the unilateral landings and propulsions associated with sprinting. Based on this meta-analysis, strength training should be incorporated prior to power training in order to establish an adequate foundation of strength for power training activities.

An acute session of roller massage prolongs voluntary torque development and diminishes evoked pain

Abstract: Roller massage (RM) has been reported to reduce pain associated with exercise-induced muscle soreness and increase range of motion without force or activation impairments. The objective was to examine RM effects on evoked pain and contractile properties. Twelve men received three sets of 30-s RM at a perceived discomfort level of 7/10 on a visual analogue scale on the ipsilateral (IPSI-R) stimulated plantar flexors (PF), contralateral PF (CONTRA-R), Sham (light rolling on stimulated PF), or Control. At pre-test, post-test, and 5-min post-test, they received evoked maximal twitch, tetanus, and 70% maximal tetanic stimulation, and performed a maximal voluntary isometric contraction (MVIC). Data analysis included perceived pain and contractile properties. The 70% tetanus illustrated significant 9–10% increases in pain perception with Sham and Control at post- and 5-min post-test, respectively (p < 0.01). There was no pain augmentation with IPSI-R and CONTRA-R. There were no main effects or interactions for most contractile properties. However, MVIC force developed in the first 200 ms showed 9.5% (p = 0.1) and 19.1% (p = 0.03) decreases with IPSI-R at post-test and 5-min post-test. Data suggest that RM-induced neural inhibition decreased MVIC F200 and nullified the testing-induced increase in evoked pain associated with 70% tetanic stimulation.

The effects of different durations of static stretching within a comprehensive warm-up on voluntary and evoked contractile properties

Abstract: Evidence for performance decrements following prolonged static stretching (SS) has led to a paradigm shift in stretching routines within a warm-up. Rather than SS, dynamic stretching (DS) and dynamic activity (DA) have replaced SS within warm-up routines. The objective of the present study was to compare the effect of differing lower limb SS durations (30 [SS30s], 60 [SS60s] or 120 s [SS120s] of SS per muscle group or no-stretch control) within a comprehensive warm-up protocol consisting of aerobic activity, DS and DA. Sixteen male participants completed the four stretching conditions in a randomized order, after a 5-min low-intensity (cycle) warm-up and before a DS/DA component on separate days. Tests included passive hip and knee ranges of motion (ROM), maximum voluntary knee extensor/flexor force, force produced at 100 ms (F100), vertical jump height and evoked knee extensor contractile properties. For hip flexion (hamstrings) ROM, SS120s provided the largest increase (5.6–11.7%) followed by SS60s (4.3–11.4%), control (4.4–10.6%) and SS30s (3.6–11.1%). For knee flexion (quadriceps) ROM, SS30s provided the largest increase (9.3–18.2%) followed by SS120s (6.5–16.3%), SS60s (7.2–15.2%) and control (6.3–15.2%). There were decreases in quadriceps F100 following SS in SS120s (29.6%) only. There were increases in vertical jump performance in the control (6.2%), SS60s (4.6%) and SS30s (3.3%). While 120 s SS per muscle increased ROM, even within a comprehensive warm-up routine, it also elicited notable performance decrements. However, moderate durations of SS were observed to improve ROM whilst either having negligible or beneficial (but not detrimental) effects on specific aspects of athletic performance.

Foam Rolling of Quadriceps Decreases Biceps Femoris Activation

Abstract: Cavanaugh, MT, Aboodarda, SJ, Hodgson, DD, and Behm, DG. Foam rolling of quadriceps decreases biceps femoris activation. J Strength Cond Res 31(8): 2238-2245, 2017-Foam rolling has been shown to increase range of motion without subsequent performance impairments of the rolled muscle, however, there are no studies examining rolling effects on antagonist muscles. The objective of this study was to determine whether foam rolling the hamstrings and/or quadriceps would affect hamstrings and quadriceps activation in men and women. Recreationally, active men (n = 10, 25 ± 4.6 years, 180.1 ± 4.4 cm, 86.5 ± 15.7 kg) and women (n = 8, 21.75 ± 3.2 years, 166.4 ± 8.8 cm, 58.9 ± 7.9 kg) had surface electromyographic activity analyzed in the dominant vastus lateralis (VL), vastus medialis (VM), and biceps femoris (BF) muscles on a single leg landing from a hurdle jump under 4 conditions. Conditions included rolling of the hamstrings, quadriceps, both muscle groups, and a control session. Biceps femoris activation significantly decreased after quadriceps foam rolling (F(1,16) = 7.45, p = 0.015, -8.9%). There were no significant changes in quadriceps activation after hamstrings foam rolling. This might be attributed to the significantly greater levels of perceived pain with quadriceps rolling applications (F(1,18) = 39.067, p < 0.001, 98.2%). There were no sex-based changes in activation after foam rolling for VL (F(6,30) = 1.31, p = 0.283), VM (F(6,30) = 1.203, p = 0.332), or BF (F(6,36) = 1.703, p = 0.199). Antagonist muscle activation may be altered after agonist foam rolling, however, it can be suggested that any changes in activation are likely a result of reciprocal inhibition due to increased agonist pain perception.

Four weeks of roller massage training did not impact range of motion, pain pressure threshold, voluntary contractile properties or jump performance.

Abstract: Background Roller massagers are popular devices that are used to improve range of motion (ROM), enhance recovery from muscle soreness, and reduce pain under acute conditions. However, the effects of roller massage training and training frequency are unknown. Purpose The objective was to compare two different roller massage training frequencies on muscle performance. Study Design Randomized controlled intervention study. Methods Twenty-three recreationally active university students were randomly allocated to three groups: control (n=8;), rolling three (3/W; n=8;) and six (6/W; n=7) times per week for four weeks. The roller massage training consisted of unilateral, dominant limb, quadriceps and hamstrings rolling (4 sets x 30 seconds). Both legs of participants were tested pre- and post-training for active and passive hamstrings and quadriceps range of motion (ROM), electromyography (EMG) activity during a lunge movement, unilateral countermovement jumps (CMJ), as well as quadriceps and hamstrings maximum voluntary isometric contraction (MVIC) forces and electromechanical delay. Finally, they were tested for pain pressure threshold at middle and distal segments of their quadriceps and hamstrings. Results There were no significant training interactions for any measure with the exception that 3/W group exhibited 6.2% (p=0.03; Effect Size: 0.31) higher CMJ height from pre- (38.6 ± 7.1 cm) to post-testing (40.9 ± 8.1 cm) for the non-dominant limb. Conclusions Whereas the literature has demonstrated acute responses to roller massage, the results of the present study demonstrate no consistent significant training-induced changes. The absence of change may highlight a lack of muscle and myofascial morphological or semi-permanent neurophysiological changes with rolling. Levels of Evidence 2c.

The Importance of Muscular Strength: Training Considerations

Abstract: This review covers underlying physiological characteristics and training considerations that may affect muscular strength including improving maximal force expression and time-limited force expression. Strength is underpinned by a combination of morphological and neural factors including muscle cross-sectional area and architecture, musculotendinous stiffness, motor unit recruitment, rate coding, motor unit synchronization, and neuromuscular inhibition. Although single- and multi-targeted block periodization models may produce the greatest strength-power benefits, concepts within each model must be considered within the limitations of the sport, athletes, and schedules. Bilateral training, eccentric training and accentuated eccentric loading, and variable resistance training may produce the greatest comprehensive strength adaptations. Bodyweight exercise, isolation exercises, plyometric exercise, unilateral exercise, and kettlebell training may be limited in their potential to improve maximal strength but are still relevant to strength development by challenging time-limited force expression and differentially challenging motor demands. Training to failure may not be necessary to improve maximum muscular strength and is likely not necessary for maximum gains in strength. Indeed, programming that combines heavy and light loads may improve strength and underpin other strength-power characteristics. Multiple sets appear to produce superior training benefits compared to single sets; however, an athlete’s training status and the dose–response relationship must be considered. While 2- to 5-min interset rest intervals may produce the greatest strength-power benefits, rest interval length may vary based an athlete’s training age, fiber type, and genetics. Weaker athletes should focus on developing strength before emphasizing power-type training. Stronger athletes may begin to emphasize power-type training while maintaining/improving their strength. Future research should investigate how best to implement accentuated eccentric loading and variable resistance training and examine how initial strength affects an athlete’s ability to improve their performance following various training methods.

Excitability changes in human forearm corticospinal projections and reflex pathways during rhythmic voluntary movement of the opposite limb

Abstract: Rhythmic movements brought about by the contraction of muscles on one side of the body give rise to phase‐locked changes in the excitability of the homologous motor pathways of the opposite limb. Such crossed facilitation should favour patterns of bimanual coordination in which homologous muscles are engaged simultaneously, and disrupt those in which the muscles are activated in an alternating fashion. In order to examine these issues, we obtained responses to transcranial magnetic stimulation (TMS), to stimulation of the cervicomedullary junction (cervicomedullary‐evoked potentials, CMEPs), to peripheral nerve stimulation (H‐reflexes and f‐waves), and elicited stretch reflexes in the relaxed right flexor carpi radialis (FCR) muscle during rhythmic (2 Hz) flexion and extension movements of the opposite (left) wrist. The potentials evoked by TMS in right FCR were potentiated during the phases of movement in which the left FCR was most strongly engaged. In contrast, CMEPs were unaffected by the movements of the opposite limb. These results suggest that there was systematic variation of the excitability of the motor cortex ipsilateral to the moving limb. H‐reflexes and stretch reflexes recorded in right FCR were modulated in phase with the activation of left FCR. As the f‐waves did not vary in corresponding fashion, it appears that the phasic modulation of the H‐reflex was mediated by presynaptic inhibition of Ia afferents. The observation that both H‐reflexes and f‐waves were depressed markedly during movements of the opposite indicates that there may also have been postsynaptic inhibition or disfacilitation of the largest motor units. Our findings indicate that the patterned modulation of excitability in motor pathways that occurs during rhythmic movements of the opposite limb is mediated primarily by interhemispheric interactions between cortical motor areas.

A Meta-Analysis of the Effects of Foam Rolling on Performance and Recovery.

Abstract: Foam rolling is thought to improve muscular performance and flexibility as well as to alleviate muscle fatigue and soreness. For this reason, foam rolling has become a popular intervention in all kinds of sport settings used to increase the efficiency of training or competition preparation as well as to speed post-exercise recovery. The objective of this meta-analysis was to compare the effects of foam rolling applied before (pre-rolling as a warm-up activity) and after (post-rolling as a recovery strategy) exercise on sprint, jump, and strength performance as well as on flexibility and muscle pain outcomes and to identify whether self-massage with a foam roller or a roller massager is more effective. A comprehensive and structured literature search was performed using the PubMed, Google Scholar, PEDro, and Cochrane Library search engines. Twenty-one studies were located that met the inclusion criteria. Fourteen studies used pre-rolling, while seven studies used post-rolling. Pre-rolling resulted in a small improvement in sprint performance (+0.7%, g = 0.28) and flexibility (+4.0%, g = 0.34), whereas the effect on jump (-1.9%, g = 0.09) and strength performance (+1.8%, g = 0.12) was negligible. Post-rolling slightly attenuated exercise-induced decreases in sprint (+3.1%, g = 0.34) and strength performance (+3.9 %, g = 0.21). It also reduced muscle pain perception (+6.0%, g = 0.47), whereas its effect on jump performance (-0.2%, g = 0.06) was trivial. Of the twenty-one studies, fourteen used foam rollers, while the other seven used roller massage bars/sticks. A tendency was found for foam rollers to offer larger effects on the recovery of strength performance (+5.6%, g = 0.27 vs. -0.1%, g = -0.01) than roller massagers. The differences in the effects between foam rolling devices in terms of pre-rolling did not seem to be of practical relevance (overall performance: +2.7 %, g = 0.11 vs. +0.4%, g = 0.21; flexibility: +5.0%, g = 0.32 vs. +1.6%, g = 0.39). Overall, it was determined that the effects of foam rolling on performance and recovery are rather minor and partly negligible, but can be relevant in some cases (e.g., to increase sprint performance and flexibility or to reduce muscle pain sensation). Evidence seems to justify the widespread use of foam rolling as a warm-up activity rather than a recovery tool.

Methodological Characteristics and Future Directions for Plyometric Jump Training Research: A Scoping Review

Abstract: Recently, there has been a proliferation of published articles on the effect of plyometric jump training, including several review articles and meta-analyses. However, these types of research articles are generally of narrow scope. Furthermore, methodological limitations among studies (e.g., a lack of active/passive control groups) prevent the generalization of results, and these factors need to be addressed by researchers. On that basis, the aims of this scoping review were to (1) characterize the main elements of plyometric jump training studies (e.g., training protocols) and (2) provide future directions for research. From 648 potentially relevant articles, 242 were eligible for inclusion in this review. The main issues identified related to an insufficient number of studies conducted in females, youths, and individual sports (~ 24.0, ~ 37.0, and ~ 12.0% of overall studies, respectively); insufficient reporting of effect size values and training prescription (~ 34.0 and ~ 55.0% of overall studies, respectively); and studies missing an active/passive control group and randomization (~ 40.0 and ~ 20.0% of overall studies, respectively). Furthermore, plyometric jump training was often combined with other training methods and added to participants’ daily training routines (~ 47.0 and ~ 39.0% of overall studies, respectively), thus distorting conclusions on its independent effects. Additionally, most studies lasted no longer than 7 weeks. In future, researchers are advised to conduct plyometric training studies of high methodological quality (e.g., randomized controlled trials). More research is needed in females, youth, and individual sports. Finally, the identification of specific dose-response relationships following plyometric training is needed to specifically tailor intervention programs, particularly in the long term.

Do Self-Myofascial Release Devices Release Myofascia? Rolling Mechanisms: A Narrative Review.

Abstract: The term “self-myofascial release” is ubiquitous in the rehabilitation and training literature and purports that the use of foam rollers and other similar devices release myofascial constrictions accumulated from scar tissue, ischaemia-induced muscle spasms and other pathologies. Myofascial tone can be modulated with rollers by changes in thixotropic properties, blood flow, and fascial hydration affecting tissue stiffness. While rollers are commonly used as a treatment for myofascial trigger points, the identification of trigger points is reported to not be highly reliable. Rolling mechanisms underlying their effect on pain suppression are not well elucidated. Other rolling-induced mechanisms to increase range of motion or reduce pain include the activation of cutaneous and fascial mechanoreceptors and interstitial type III and IV afferents that modulate sympathetic/parasympathetic activation as well as the activation of global pain modulatory systems and reflex-induced reductions in muscle and myofascial tone. This review submits that there is insufficient evidence to support that the primary mechanisms underlying rolling and other similar devices are the release of myofascial restrictions and thus the term “self-myofascial release” devices is misleading.