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Impact of Fat Grip Attachments on Muscular Strength and Neuromuscular Activation During Resistance Exercise
Abstract
Abstract Krings, BM, Shepherd, BD, Swain, JC, Turner, AJ, Chander, H, Waldman, HS, McAllister, MJ, Knight, AC, and Smith, JW. Impact of fat grip attachments on muscular strength and neuromuscular activation during resistance exercise. J Strength Cond Res XX(X): 000–000, 2018—The purpose of this study was to examine the acute effects of Fat Gripz (FG) on muscular activation and strength. Resistance trained men (n = 15; age = 22.4 ± 2.3 years; mass = 83.2 ± 11.1 kg) performed 2 experimental trials in a randomized order. Subjects completed 1 repetition maximum (1RM) testing with an Olympic barbell (OB) and with FG attached to an OB during the exercises of deadlift, bent-over row, upright row, concentration curl, and completed maximum repetitions of pull-ups until failure. Surface electromyography (EMG) was used to measure muscle activity from 8 upper extremity muscles (trapezius, medial deltoid, biceps brachii, triceps brachii, flexor carpi radialis, flexor carpi ulnaris, extensor carpi radialis, and extensor carpi ulnaris), while performing maximal voluntary isometric contractions during 1RM trials and while performing maximum number of pull-ups. When using the FG, 1RM strength was significantly decreased for each exercise, and the maximal number of pull-ups completed was significantly lower. Electromyography muscle activity was significantly increased in the forearm and shoulder muscles, but significantly decreased in the upper arm muscles with the use of FG during deadlift, bent-over row, and pull-ups. However, there were no differences for EMG activity for upright row and concentration curl. Differences in maximal strength, pull-up performance, and EMG activity with FG use may be due to the different muscle length positions. Although FG training may increase neuromuscular activation, decrements in muscular strength may result in prescribing low training loads that may not be ideal for building muscular strength.
... No common criteria were followed when referring to the exercise loading at which exercises were evaluated during sEMG recordings. As a matter of fact, only two studies used a similar method, assessing one repetition maximum intensity (1RM) [22,32]. Some studies measured a number of repetitions of xRM, whereas others measured a number of repetitions of a range between 65-85% of 1RM (Table 1), which could be considered in all cases as a submaximal load intensity [33]. ...
... The included studies were variate in number of participants (8-34) but similar in their sample population ages (18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34), who had a minimum of 6 months resistance training experience. It is important to highlight the impact that training status have upon muscle activation pattern, since familiarization with the movement could substantially modify muscle activation elicited during each exercise [49][50][51]. ...
... Eight studies following the SENIAM Guidelines have been included in our review [8, 16, 22, 35-37, 41, 42]. The rest followed some other Guidelines or a previous reference, and only four studies did not report any protocol for electrode location [26,28,32,34]. ...
The main purpose of this review was to systematically analyze the literature concerning studies which have investigated muscle activation when performing the Deadlift exercise and its variants. This study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Statement (PRISMA). Original studies from inception until March 2019 were sourced from four electronic databases including PubMed, OVID, Scopus and Web of Science. Inclusion criteria were as follows: (a) a cross-sectional or longitudinal study design; (b) evaluation of neuromuscular activation during Deadlift exercise or variants; (c) inclusion of healthy and trained participants, with no injury issues at least for six months before measurements; and (d) analyzed “sEMG amplitude”, “muscle activation” or “muscular activity” with surface electromyography (sEMG) devices. Major findings indicate that the biceps femoris is the most studied muscle, followed by gluteus maximus, vastus lateralis and erector spinae. Erector spinae and quadriceps muscles reported greater activation than gluteus maximus and biceps femoris muscles during Deadlift exercise and its variants. However, the Romanian Deadlift is associated with lower activation for erector spinae than for biceps femoris and semitendinosus. Deadlift also showed greater activation of the quadriceps muscles than the gluteus maximus and hamstring muscles. In general, semitendinosus muscle activation predominates over that of biceps femoris within hamstring muscles complex. In conclusion 1) Biceps femoris is the most evaluated muscle, followed by gluteus maximus, vastus lateralis and erector spinae during Deadlift exercises; 2) Erector spinae and quadriceps muscles are more activated than gluteus maximus and biceps femoris muscles within Deadlift exercises; 3) Within the hamstring muscles complex, semitendinosus elicits slightly greater muscle activation than biceps femoris during Deadlift exercises; and 4) A unified criterion upon methodology is necessary in order to report reliable outcomes when using surface electromyography recordings.
... This articular stress could also be related to the handle conception. Indeed, the handle diameter has to be considered, since a too thick handle has been reported to decrease grip strength and increase grip fatigability (Krings et al., 2021). Maximal grip strength has been found for handle diameters varying between 25 and 40 mm (Rossi et al., 2012). ...
... Although the ergonomic handle provided an overall better comfort, its diameter might not be optimized as reported by the lack of improvement rated by the rowers for this item. Accordingly, adapting the handle diameters to the user's hand length could increase grip force and gripping comfort (Kong and Lowe, 2005;Wang and Cai, 2017;Krings et al., 2021). An improved individualized version of the handle, adapted to the user's hand length could potentially further improve performance. ...
... This articular stress could also be related to the handle conception. Indeed, the handle diameter has to be considered, since a too thick handle has been reported to decrease grip strength and increase grip fatigability (Krings et al., 2021). Maximal grip strength has been found for handle diameters varying between 25 and 40 mm (Rossi et al., 2012). ...
... Although the ergonomic handle provided an overall better comfort, its diameter might not be optimized as reported by the lack of improvement rated by the rowers for this item. Accordingly, adapting the handle diameters to the user's hand length could increase grip force and gripping comfort (Kong and Lowe, 2005;Wang and Cai, 2017;Krings et al., 2021). An improved individualized version of the handle, adapted to the user's hand length could potentially further improve performance. ...
Articular stress and discomfort during repetitive movements may impact the risk of injuries of the upper limbs during ergometer rowing, especially when using a regular circular handle. Therefore, the purpose of the study was to propose and evaluate the influence of an ergonomic handle on upper limbs biomechanics, comfort and performance during ergometer rowing. An ergonomic irregular hexagon handle, with a 1:1.25 width/length diameters ratio, has been developed. Left upper limb kinematics and neuromuscular activity, perceived comfort and power production were monitored for 29 expert rowers. The ergonomic handle increased the perceived comfort while maintaining the overall articular stress and performance as the same level compared to the regular handle. We recommend using irregular hexagon handles with 1:1.25 ratio for ergometer rowing. Further improvements of the ergonomic handle such as an individualization based on the user's hand length may further enhance comfort and achieve better performance.
Deadlift is a measure of the overall strength of the whole body and it is one of the three exercises in the powerlifting competition. There are conventional and sumo variant of deadlift. The aim of this study was to determine the differences between the two lifting techniques from the aspect of kinematics, kinetics and electromyography. Nine physically active men, average age 29.1 ± 3.3 years, body height 181.0 ± 1.0 cm, body weight 82.3 ± 13.3 kg and body massindex 25.0 ± 3.8 kg/m2 were recruited forthisstudy. Each subject lifted weight close to his own body weight with three repetitions, in three series, for each of the techniques. The speed of one lift was 3 seconds for each of the phases (concentric and eccentric). The angles and amplitudes for the following figurative points were monitored: trunk in relation to the horizontal plane (angle), center of the hip joint and center of the knee joint in the "liftoff" (LO - position in which the weight separates from the ground) and "knee passing" (KP - position in which the weight passes in front of the knee position), i.e. in the liftoff-knee passing (LO-KP), knee passing-lift completion (KP-LC; LC - final, i.e. completely upright body position) and liftoff-lift completion (LOLC) phase. The mechanical work was monitored as a one of the kinetic variables. Electromyographic activity was monitored for the following muscles: m. vastus medialis, m. vastus lateralis, m. rectus femoris, m. gluteus Maximus, m. erector spinae (L3-L4), m. semimembranosus and m. biceps femoris caput longum. The monitored electromyographic variablewasthe average normalized amount of muscle activation in relation to maximal voluntary contraction, for all 18 individual deadlift repetitions (3 series × 3 repetitions × 2 techniques). One-way analysis of variance with repeated measurements (for the amount of muscle activation and performed mechanical work) and two-way analysis of variance with repeated measurements (for angles and amplitudes) were used for statistical data processing. Significant differences were found between techniques in the initial angular positions in all monitored joints (p<0.05), except for the angle in the knee joint where the trend was observed (p=0.0996), as well as in the transit position for the trunk angle relative to the horizontal plane and angle at the hip joint (p<0.05). There was a statistically significant difference between techniques in amplitudes in the hip joint during KP-LC phase (p<0.05) and total amplitude (p<0.05), as well as in the knee joint during LO-KP phase (p<0.05) and total amplitude in the form of a trend (p=0.0996). The performed mechanical work is significantly higher when lifting the load with the conventional deadlift technique (DLcon) (p<0.05). Activation of medial and lateral heads of m. quadriceps femoris is significantly higher (p<0.05) when lifting with sumo deadlift technique (DLsu). It was noticed that activation of postural muscle groups (m. erector spinae, m. gluteus maximum, m. semitendinosus and m. biceps femoris caput longum) is higher when lifting the load with DLcon, but not significantly (p>0.05).
Background
The three portions of the deltoid muscle (anterior, middle, and posterior) are primary movers of several strengthening exercises and their contribution to different exercises can be measured using surface electromyography.
Purpose
To systematically review studies that evaluated the activation of commonly used exercises and their variations.
Methods
A search was conducted in PubMed (MEDLINE), Web of Science, Scopus and SciELO. Thirty-three studies met the inclusion criteria, evaluating at least one deltoid portion during conventional isotonic exercises (minimum load: 60% of one-repetition maximum or body weight) and reporting normalized values. Similar exercises were grouped, averaged, and ranked according to the resulting activation. Individual exercise variations were also ranked.
Results
For anterior deltoid, horizontal adductions (inclined) and horizontal adductions (horizontal) generated the greatest activation, while the inclined dumbbell fly was the individual exercise with greatest activation; for middle deltoid, abductions and horizontal abductions presented the greatest activation, with lateral raises associated with internal rotation being the exercises producing greatest activation. For posterior deltoid, pull-ups generated greatest activation, with the standard pull-up and the inverted row with a suspension device requiring the greatest individual exercise activation.
Conclusions
These findings can be useful for coaches and practitioners when choosing the most appropriate exercise for strengthening programs.
PURPOSE:There are various variables such as exercise posture, exercise intensity, number of repetitions, and rest time of training for muscle strength development, and these variables are intended to stimulate muscle activity. The purpose of this study was to examine the effects of muscle activation according to grip thickness in pull-up exercise.METHODS: Eleven healthy men were randomly crossover design assigned to pull-up exercise (concentric: 1-s, eccentric: 1-s, 2-s/repetition) to failure. Surface electromyography (EMG) was recorded from the forearm flexors/extensors, biceps brachii, trapezius middle/lower and latissimus dorsi for muscle activation. Using the resulting EMG data, which were filtered of electromyogram artifacts, we calculated the root mean squares (RMS).RESULTS: Dependent-sample t-test produced a result, muscle activity in forearm flexors (p<.01), biceps brachii (p<.01), trapezius middle (p<.01), trapezius lower (p<.01) and latissimus dorsi (p<.05) were significantly increased at thick grip compared to normal grip in pull-up exercise.CONCLUSIONS:This study suggested that the thicker the grip, the higher the muscle activation. Using a grip thickness as one of the variables for training programs is considered as a method to stimulate muscle activity.
The objective of this study was to analyse the effect of the handle diameter on the grip forces exerted by the hand during a maximal power grip task. A handle ergometer, combining six instrumented beams and a pressure map, was used to determine the forces exerted by the palm side of the hand regrouping data from 10 anatomical sites (fingertips, phalanges, thumb, palm…). This methodology provided results giving new insight into the effect of the handle diameter on the forces exerted by the hand. First, it appeared that the relationship between the hand length/handle diameter ratio and the maximal grip force fit a U-inverted curve with maximal values observed for a handle diameter measuring 17.9% of the hand length. Second, it was showed that the handle diameter influenced the forces exerted on the anatomical sites of the hand. Finally, it was showed that the handle diameter influenced the finger force sharing particularly for the index and the little fingers. Practitioner Summary: This study analysed the effect of the handle diameter on the grip forces exerted by the hand during a maximal power grip force. This study showed that measurement of the totality of the forces exerted at the hand/handle interface is needed to better understand the ergonomics of handle tools. Our results could be re-used by designers and clinicians in order to develop handle tools which prevent hand pathologies.
Grip force was measured along two orthogonal axes and vector summed. Sixty-one participants recruited from a manufacturing facility (29 men and 32 women) grasped instrumented cylinders (2.54, 3.81, 5.08, 6.35, and 7.62 cm diameter) using a maximal voluntary power grip. Two orthogonal force measurements relative to the third metacarpal were resolved into a magnitude and corresponding angle. On average, magnitude increased 34.8 N as handle diameter increased from 2.54 cm to 3.81 cm, and then monotonically declined 103.8 N as the handle diameter increased to 7.62 cm. The average direction monotonically decreased from 59.2 degrees to 37.7 degrees as handle diameter decreased from the largest to the smallest. When the diameter was smallest, the greatest force component, Fx (168.6 N), was in the direction where the fingertips opposed the palm. Conversely, when the diameter was largest, the smallest component, Fx (77.7 N), was in the same direction. These values are averaged for the left and right hand. The angle for the largest diameter increased with increasing hand size. These relationships should be useful for the design of handles that require gripping in specific directions, such as for hand tools and controls. Actual or potential applications of this research include the design of handles that require gripping in specific directions, such as for hand tools and controls, that reduce effort, and that prevent fatigue and overexertion.
Inappropriately sized tennis racket grip is often cited in the popular media as a risk factor for overuse injuries about the forearm and elbow. Currently, a hand measurement technique developed by Nirschl is commonly used by tennis racket manufacturing companies as the method for determining a player's "recommended" grip size.
Quarter-inch changes from that recommended by Nirschl in tennis racket grip size will have no significant effect on forearm muscle firing patterns.
Controlled laboratory study.
Sixteen asymptomatic Division I and II collegiate tennis players performed single-handed backhand ground strokes with rackets of 3 different grip sizes (recommended measurement, undersized (1/4) in, and oversized (1/4) in). Fine-wire electromyography was used to measure muscle activity in extensor carpi radialis longus and brevis, extensor digitorum communis, flexor carpi radialis, and pronator teres. Repeated-measure analysis of variance was used for within-group comparisons, comparing different grips in specified phases for backhand ground strokes (P <or= .05).
There were no significant differences in muscle activity between small, recommended, or big grips in any muscle tested.
Based on these findings, tennis racket grip size (1/4) in above or below Nirschl's recommended measurement does not significantly affect forearm muscle firing patterns.
Alterations in tennis racket grip size within (1/4) in of Nirschl's recommended sizing do not have a significant effect on forearm muscle activity and therefore may not represent a significant risk factor for upper extremity cumulative trauma, such as lateral epicondylitis.
Biomechanical principles indicate that the risk of upper extremity cumulative trauma disorders (CTDs) can be mitigated by designing tools to reduce manual effort. Specifically, research suggests that handle design should be based on anthropometric considerations. A laboratory study was designed to evaluate the effects of handle diameter on manual effort during a simulated industrial task. Three handle diameters were studied: (1) a handle matched to inside grip diameter, (2) a handle 1.0 cm smaller than inside grip diameter, and (3) a handle 1.0 cm larger than inside grip diameter. The task was performed against three levels of resistance. Applied grip force and surface electromyography (EMG) of select forearm muscles were recorded. The results indicate that grip strength was maximized by the smaller handle. Grip strength was also greater with the matched handle than with the larger handle. There were no differences in grip force exerted with different handles during the experiment. However, because the smaller handle provided the greatest capacity for exerting grip force, effort was reduced when the smaller handle was used. Forearm muscle activity was also reduced when the smaller handle was used. The study indicates handles 1.0 cm smaller than the user's inside grip diameter may reduce effort and the potential for injury.
This study tested maximum grip force on cylindrical aluminum handles to evaluate the relationships between handle diameter (25–50 mm diameter handles), perceived comfort, finger and phalange force distribution, and electromyographic efficiency of finger flexor and extensor muscle activity. A force glove system containing 16 thin profile force sensors was developed to measure finger and phalangeal forces on the cylindrical handles. Participants (n=24) rated the mid-sized handles (30, 35 and 40 mm) as the most comfortable for maximum grip force exertions. Using a polynomial regression the handle diameter that maximized subjective comfort was calculated as a function of the user's hand length. This optimal handle diameter was 19.7% of the user's hand length. Total finger force capability was inversely related with handle diameter. Electromyographic amplitude of the primary flexor and extensor was unaffected by handle diameter, so the efficiency of the muscle electrical activity followed the same relationship with handle diameter as total finger force. Individual finger and phalange force distributions were examined to evaluate their relationship with perceived comfort. A non-uniform finger/phalange force distribution, in which finger force was proportional to finger muscle capabilities, exhibited a stronger correlation with subjective ratings of comfort than a uniform finger/phalange force distribution.Relevance to industryResults obtained in this study will provide guidelines to hand-tool designers and manufacturers for maximizing handle comfort based on the user's hand size.
The purpose of this study was to examine the influence of two different bar diameters on neuromuscular activation and strength. The bar diameters used reflected a standard Olympic bar (28 mm (1.1 inch); THIN) and a larger fat bar (51 mm [2 inch]; THICK). Eighteen healthy men (age 25.0 +/- 1 years) were assessed for their maximal voluntary contraction (MVC) during a unilateral isometric bench press exercise with the 2 bar types at 2 different joint angles (angle 1 and angle 2; elbow joint at approximately 45 and 90 degrees , respectively). Additionally, on a separate day, subjects performed three 10-second isometric repetitions at an intensity of 80% MVC using the 2 different bars at angle 1 and angle 2. Electromyographic recordings were collected in the pectoralis major and the muscles of the forearm flexor region at a sampling rate of 1000 Hz during the second day of testing. Analysis of variance was used to examine differences in MVC between bars and also examine between bar differences in electromyographic activity for each muscle group at each joint angle. A significance level of 0.05 was used for all tests. MVC was not different between bar types, although there was a main effect of joint angle on MVC such that it was greater at angle 2. There was a main effect of bar at both angles for the forearm muscles and at angle 1 for the pectoralis such that electromyographic activity was greater with THIN. Our data do not support the hypothesis that bar diameter influences performance during an isometric bench press exercise. However, higher electromyographic activity with THIN suggests greater neuromuscular activation with a standard Olympic bar as opposed to a larger diameter "fat" bar. Although our data do not support the use of a fat bar for increasing neuromuscular activation, these findings should be confirmed in other resistance training exercises.
An investigation of maximal isometric cylindrical grasping actions of the hand is reported. A dynamometer is described which allows simultaneous measurement of both the normal forces and the tangential shear forces imposed by each of the three phalangeal segments of a finger during a test. Seventeen subjects were tested, grasping cylinders 31-116 mm in diameter. Normal grasp forces decreased significantly as cylinder size increased, while with large diameters, shear forces moved the skin towards the finger tip. In all cases the distal segments of the fingers imposed forces significantly larger than those of the middle and proximal segments. The mean contributions of fingers from index to little were: 30, 30, 22 and 18%, proportions that did not vary significantly for the range of grasp diameters. Forces acting during grasping activities are reported in greater detail, for a wider range of hand gripping postures, than previously available. These data are useful in the design of hand operated controls or in the prediction of tendon and joint forces in vivo for the design of implants.
The aim of this study was to investigate the effect of grip span on isometric grip force and fatigue of the flexor digitorum superficialis (FDS) muscle during sustained voluntary contractions at 60-65% of the maximal voluntary contraction (MVC). Eighteen subjects performed isometric, submaximal gripping contractions using a grip dynamometer at four different grip span settings while the pronated forearm rested on a horizontal surface. Maximal absolute grip force and median power frequency of FDS surface electromyography (EMG) during the submaximal trials were analyzed. Fatigue of FDS, as inferred from EMG frequency shifts, did not change as a function of grip size. However, middle grip sizes allowed for greater absolute forces than the small or large size. When contractions are at 60-65% MVC and the muscle is allowed to fatigue, however, grip size may be less influential than when maximal absolute force is required.
The purpose of the present investigation was to examine strength performance of 6 common resistance training exercises using free weight bars of different thickness. Eleven resistance-trained men (8.2 +/- 2.6 years of experience; age: 22.1 +/- 1.6 years; body mass: 90.5 +/- 8.9 kg) underwent 1 repetition maximum (1RM) strength testing on 6 occasions in random order for the deadlift, bent-over row, upright row, bench press, seated shoulder press, and arm curl exercises under 3 conditions using: (a) a standard Olympic bar (OL), (b) a 2-inch thick bar (5.08 cm grip span), and (c) a 3-inch thick bar (7.62 cm grip span). Significant (p < 0.05) interactions were observed for the "pulling" exercises. For the deadlift and bent-over row, highest 1RM values were obtained with OL, followed by the 2- and 3-inch bar. Significant 1RM performance decrements for the 2- and 3-inch bars were approximately 28.3 and 55.0%, respectively, for the deadlift; decrements for the 2- and 3-inch bars were approximately 8.9 and 37.3%, respectively, for the bent-over row. For the upright row and arm curl, similar 1RMs were obtained for OL and the 2-inch bar. However, a significant performance reduction was observed using the 3-inch bar (approximately 26.1% for the upright row and 17.6% for the arm curl). The reductions in 1RM loads correlated significantly to hand size and maximal isometric grip strength (r = -0.55 to -0.73). No differences were observed between bars for the bench press or shoulder press. In conclusion, the use of 2- and 3-inch thick bars may result in initial weight reductions primarily for pulling exercises presumably due to greater reliance on maximal grip strength and larger hand size.
Effects of fat grip training on muscular strength and driving performance in Division I male golfers
- P M Cummings
- Waldman
- Hs
- Krings
- Bm
- J W Smith
- M J Mcallister
Cummings, PM, Waldman, HS, Krings, BM, Smith, JW, and
McAllister, MJ. Effects of fat grip training on muscular strength and
driving performance in Division I male golfers. J Strength Cond Res
32: 205-210, 2018.
Essentials of Strength Training and Conditioning
- Haff
- N T Triplett
Haff, GG and Triplett, NT. Essentials of Strength Training and
Conditioning. Champaign, IL: Human Kinetics, 2015. pp. 175-439.
Effects of fat grip training on muscular strength and driving performance in Division I male golfers
- Cummings
Acute muscular strength assessment using free weight bars of different thickness
- Ratamess