By Bob Alejo
Grip strength is a huge topic. It is often associated with performance enhancement and not just with those sports that common sense would lead you to think of first—baseball, judo, racquet sports, strong man competitions, etc. Programs dedicate time to specifically train grip. But is it just one of those things we talk about as being important or do we focus on it as a necessary component because there will be a glaring weakness if we don’t train it? Is it merely another one of those things that everyone talks about, so it must be true?
Well, I’m here to tell you the information out there is pretty clear and also inconclusive, at the same time. I’d be lying if I said I wasn’t surprised. Let me explain.How important is grip strength? The supporting information is pretty clear, and also inconclusive. Click To Tweet
Several factors influence grip strength: age, sex, hand size and grip span, posture, and position of the shoulder, forearm, and wrist (Espana-Romero et al., 2010). When you add in the validity and reliability of the dynamometer, the settings used for the test, and the different protocols, it’s easy to see that testing for grip strength is a cloudy proposition at best. In the Espana-Romero study alone, there were different results using the same test protocol but three different dynamometers!
Look, for sure if you can’t hold something well in sports (ball, bat, jersey, judo gi, barbell), your success is limited. My question is how much importance and commitment should be put on improving grip strength and what support exists beyond “I think it helps our athletes.”
Where Do the Studies Come From?
While I focused on athletic-related information, I found a tremendous amount of work on everything but that. As Mike Young (PhD, Athletic Lab owner and founder, member of Power Lift’s Sports Science Educational Board) pointed out to me and I found to be true, there’s a great amount of grip strength work related to mortality, wellness, quality of life and aging, and specific diseases like CPD, arthritis, diabetes, and hypo/hyperthyroidism.
Roberts et al. (2011) concur, as illustrated in the introduction portion of their review: “As an assessment measure, grip strength has been shown to have predictive validity and low values are associated with falls (Sayer et al., 2006), disability, impaired health-related quality of life (Syddall et al., 2009), and prolonged length of stay in hospital (Kerr et al., 2006), as well as increased mortality (Gale et al., 2007; Cooper et al., 2010).” It’s a simple and apparently obvious tool when looking at wellness. Other health-related handgrip studies include: LeWine, 2016; Pedão et al., 2014; Syddall et al., 2009; and Cooper et al., 2010.
On the other hand, athletic studies come from all levels—male, female, adolescents, high school, collegiate, and non-elite. I will cite some of the sparse information on elite and professional athletes in this article.
The Validity and Reliability of Grip Strength Testing
Before going all in on grip strength as a performance assessment, you’d have to start with the validity and reliability of the grip testing: both the protocol and the instrument. It is definitely more muddled than the results themselves. In the Espana-Romero study again, for example, the position of the elbow AND the dynamometer used (as I mentioned, three were in the study) have conflicting results in the same study.
The researchers looked at how elbow position affected grip strength in 12-16-year-old males and females using the TKK, Jamar, and DynEx dynamometers. Without going into too much detail, strength levels were significantly higher when the elbow was flexed at 90 degrees with the TKK. Results of the study indicate that of the three dynamometers, the TKK offered the highest validity and reliability for that “particular population,” if for no other reason than the TKK could be adjusted to 12-16-year old hand size whereas the Jamar and DynEx were not practical to accommodate that size.
When working with college hockey and possible future NHLers, comparison to NHL Combine grip testing scores would make sense for goal setting and programming. The NHL Combine uses the Jamar dynamometer for grip strength testing. For the test, the athletes put their arm overhead and fully extend it, squeeze the dynamometer as tightly as possible, and slowly release their arm down to their side (Chiarlitti et al., 2017). I thought it odd to have a grip test overhead until I read a study (Su et al., 1994) showing that the shoulder flexed at 180 degrees (overhead) and arm fully extended had the highest mean grip (using the Jamar) out of four positions (shoulder flexed at 0-90-180 degrees, and elbow flexed at 90 degrees/0 degrees shoulder flexion).
The point is that each dynamometer has its virtues and limitations in measurement of error, validity, and reliability. Different populations (age, sex, gender) are also affected by not only the dynamometer, but the protocol as well. The following are some additional references that include the topics of validity, reliability, and test protocols: Cardenas-Sanchez et al., 2016; Roberts et al., 2011; and Yingling et al., 2017.
Grip Training vs. Forearm Training: They’re Not the Same Thing
Here it is—doing wrist curls is forearm training. Opening and closing your hand is grip training. Sure, you get grip training just from weight training (as illustrated in most studies) and isometric strength is important (pinching, holding), but flexion and extension of the gripping muscles is the only way to comprehensively train the grip from an anatomical and kinesiological perspective.Doing wrist curls is forearm training—opening and closing your hand is grip training. Click To Tweet
Think about it: In what other area do we ONLY do isometric training? The grip is comprised of the strength of each finger and often the thumb. While forearm strength is important, there is no way to get to that strength if the grip “gives out”—if it’s not strong enough. If you are in a sport that requires forearm strength via the grip, you must give training the grip, including finger strength, equal training time for both volume and intensity.
I ran into a few great hand studies in engineering and ergonomic journals that were very enlightening from a data standpoint. Amis (1987) published a study that is critical for all of us in sports performance. It was an investigation of “maximal isometric cylindrical grasping actions” of cylinders 31-116 mm (1.22-4.56 in.) in diameter. He was able to measure all three phalangeal segments of each finger and their force contribution to grip and found 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.” As the cylinder size increased, grasp forces decreased. Simply—and I see very little of it—finger training is grip training.
Another study looked at isometric gripping force on five cylinders of different sizes (Edgren et al., 2004): 2.54 cm (1 in.), 3.81 cm (1.5 in.), 5.08 cm (2 in.), 6.35 cm (2.5 in.), and 7.62 cm (3 in.). Edgren goes on to note that “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 7.62 cm “handle” data from this research (the study was to benefit those designing tool handle sizes, optimizing grip for varying hand sizes) showed the smallest force. That both the smallest and largest cylinders showed the least amount of force illustrates the role of hand size and finger strength capabilities.Comprehensively train the grip by flexing and extending the fingers, like you would any muscle. Click To Tweet
These two studies clearly demonstrate the contribution of the fingers to grip strength. Training must include different-sized training widths for isometric gripping, and gripping strength should be trained with a full range of gripping motion. Comprehensively train the grip by flexing and extending the fingers, like you would any muscle in the body.
Does Grip Strength Make Us Better at Sports?
There has been a very recent review addressing exactly this question: “A brief review of handgrip strength and sport performance” (Cronin et al., 2017; 203 references). A full discussion on the validity and reliability of dynamometers and protocols, this review covers the spectrum of sports and the relationship of handgrip strength and performance. The following is a mix of quotes and paraphrased summary:
Two sporting grips were deemed common, or at least a variation of the two:
- Precision grip—used for grasping sphere-shaped objects (e.g., balls)
- Power grip—used for grasping cylindrical-shaped objects (e.g., clubs, bats, rackets, sticks, and paddles).
The study was divided into five categories:
- Stick, club, bat, racket, and ball sports
- Water sports
- Climbing and gymnastics
- Combat sports
- Strength disciplines
1. Handgrip Strength in Stick, Club, Bat, Racket, and Ball Sports
“Trivial to nearly perfect correlations” were found between handgrip strength and throwing velocity; throwing energy; cricket bowling accuracy; 10-pin bowling accuracy; bat, club, and stick/puck speed; bat energy; ﬁelding percentage; and golf, ﬁeld hockey, ice hockey, and lacrosse shot. The authors suggest that handgrip strength has less of a relationship with actions that have a “high amount of technical precision and accuracy.”
This information suggests that the timing and sequencing of the force applied to an implement or object by the hand (palm, digits, and thumb) in sport is of greater importance than the magnitude of applied force alone. In addition, perhaps a handgrip strength threshold is reached where gaining more strength is of no advantage “where the coordination and timing (e.g., bat, club, stick, and racket sports) of skilled actions is more important.”
“Strength (e.g., bench press strength and wrist, elbow, shoulder, and knee torque), ballistic (e.g., medicine ball throw distance, and bench throw velocity and power), ﬂexibility (e.g., shoulder and wrist), and anthropometric (e.g., body mass, lean mass, height, and arm span) measures were also moderately to very largely correlated with serving, spiking, and throwing velocity in tennis, volleyball, and handball athletes, respectively.” Ergo, when two or more key variables are analyzed, they better predict performance-based measures than any one variable (grip strength).
2. Handgrip Strength in Water Sports
In water sports, the hand is usually involved in propulsion through the water in some form. “Other single and multiple measures of strength (e.g., tethered swim force, upper arm, shoulder, and abdominal ﬂexion), along with horizontal jump performance, aerobic and anaerobic capacity, anthropometry (e.g., height, arm span, and foot length), and ﬂexibility (ankle and shoulder range of motion) are of equal or greater importance (than grip strength) to predicting swim performance in adolescent, teenage, and adult swimmers.”
Even though there were moderate to large correlations between handgrip strength and throwing velocity in elite water polo athletes, it was found that “certain anthropometric characteristics, such as limb length, height, lean muscle mass, and somatotype along with throwing technique, may be greater predictors of throwing velocity in water polo athletes.”
3. Handgrip Strength in Climbing and Gymnastics
The average observer would think, as the correlated and comparative information showed, there is plenty of good evidence suggesting that “a high amount of relative HGS is advantageous” for success in climbing and gymnastics (rings, bars). Although the research is limited, one study had a very large correlation between handgrip strength and handgrip strength endurance in ring athletes. With relative body mass being as important for climbing as in gymnastics, “large to very large correlations were observed between maximum relative hand grip strength, crimp grip strength, pinch grip strength, and rock climbing ability.”
4. Handgrip Strength in Combat Sports
Handgrip strength for combat sports (boxing, mixed martial arts, wrestling) seems more applicable than in a lot of sports. Although the studies with great correlations were not unanimous, there were moderate and very large relationships found between HGS and wrestling success and boxing competition ranking. Related to those data points, elite male athletes had much larger handgrip strength production than sub-elite groups, as did elite adult over sub-elite adults.
Elite combat sport athletes seem to possess greater overall maximum strength, explosive strength, lower-body fat percentages, and greater aerobic and anaerobic capacities in comparison with amateur and sub-elite combat sport athletes. It makes sense.
Comparing the grip strength of elite and non-elite Brazilian jiujitsu players (Da Silva et al., 2012) found tests that were reliable and sport-specific: “Considering that endurance as well as the grip on the lapel of the opponent’s kimono are vital to success in grappling combat sports, it seems these tests (maximum static lift and maximum number of repetitions) can be an important aspect of the physical evaluation of these athletes. In fact, our results showed elite athletes were superior in performance when compared to recreational practitioners of BJJ.”
5. Strength Athletes
Due to a lack of current research examining handgrip strength in strength athletes, only a small cohort could be reviewed. While not a specific handgrip study, Fry et al., 2006, observed large differences between the elite (stronger) and sub-elite junior Olympic weightlifters. As in other previously noted studies, the stronger grip group was also “more impulsive (i.e., vertical jump) and stronger across all lifts (i.e., snatch, clean and jerk, front squat, back squat, and bench press).”
Note: “Efficacy off Handgrip Strength in Predicting Total Body Strength Among High Performance Athletes” (Jawan et. al., 2014) was an interesting piece. I only had access to an abridged version of the full text. From what I could find out, including the abstract, the high-performance athletes (N=100; 21 sports; team and individual sports) used in this study “represented their university, state, or country in sports and were reported as being healthy and fit through the interview sessions held before selecting them into the program.”
Oddly, this study found no significant correlation between handgrip strength and “all the 1RM tests, including the bench press, lat pull-down, the leg press, leg extension, and strength test. Likewise, the leg power test also showed no significant correlation with the handgrip strength test. Hence, this study showed that the handgrip was not a significant measure of total body strength of high-performance athletes.” It was really the only study I read that showed no correlation between overall strength and handgrip strength.
Baseball has some very good grip strength studies, although not many at the MLB level. However, the information is enough to develop some pretty good suppositions. It’s pretty simple: Swinging a bat, hitting, and throwing a ball with a strong grip could be beneficial. Spaniol (2009) sums it up in his article about a baseball-specific test battery he proposed: “It is strongly suggested that one such test, grip strength, be included in the assessment process because research suggests a positive relationship between grip strength and throwing velocity, bat speed, and batted-ball velocity.”Grip strength plays a role in baseball, but not the most critical role. Click To Tweet
It’s also clear that there is a significant difference (stronger) in grip strength from high school to NCAA NAIA to specifically NCAA DI. I would say age has something to do with the increase from high school to college and perhaps skill level influences the differences between NAIA and DI college players. Nonetheless, grip plays a role. Additionally, based on the kinetic chain involved in hitting, grip strength does not play the most critical role.
The following is a summary of a few studies that should stimulate some thought:
Fry et al., 2011 – For NCAA DI baseball players, there was a significant relationship between batted ball velocity, grip strength, and incline bench press; squat strength was not significantly correlated. Eleven of the 31 participants had played a season prior to the study, so there were performance statistics to compare. For the 11, grip strength was significantly correlated to slugging percentage but “non-signiﬁcantly” to batting average. Also reported was that grip strength was lower than previous studies, perhaps due to a “different hand grip dynamometer used.”
Hoffman et al., 2009 – Signiﬁcant bivariate correlations were found between grip strength and home runs, total bases, and slugging percentage. Speed and lower body power were also significantly correlated with baseball specific performance variables.
Mangine et al., 2013 – Assessing professional pitchers and position players from under-20 to 35+ years of age (seven groups divided into three-year increments: under 20, 20-22, 23-25, etc.), of the eight total variables measured, grip strength, lean body mass, and total mass were the only variables to peak in the 29-31 age group; others peaked at a younger age.
Watanabe et al., 2017 – Vertical jump height correlated with individual performance records (total bases, slugging percentage, and stolen bases) of professional Japanese female baseball athletes. Grip, back, and lower-limb strength, and hamstring “extensibility” were not significantly correlated with game performance.
Kohmura et al., 2008 – This study proposed a testing protocol for college players that did not include grip strength. Most baseball studies typically include a gripping test as some assessment.
Szymanski and colleagues [2004, 2006, 2009, 2010, 2010] – In two articles (2009 & 2010), statistically significant relationships were demonstrated between grip strength, bat-end speed, and batted-ball exit speed in adolescent, high school-aged, and college athletes. In other articles (2004, 2006, 2010), grip strength training and a traditional (stepwise periodized) total body strength training significantly increased forearm and grip strength.
The group that completed additional grip strength and forearm training had statistically greater improvements in the seven grip and forearm variables tested compared to the control group; however, the additional supplemental grip strength and forearm training group did not have any further improvements in bat velocity (BV), center of percussion velocity (sweet spot; CV), or hand velocity (HV) in high school baseball players, indicating that a total body weight training program “…alone is a sound approach to statistically increase linear BV, CV, and HV in high school baseball players.”
Kinetic chain impact on swinging/rotating with an implement—in this case, a bat—is not related to any one variable. Improving kinematics and kinetics (forces that cause motion) of swinging a baseball bat is more complex and, in general, related to proper swing mechanics and power. (Many thanks to my friend and colleague, David Szymanski for co-authoring these two paragraphs with me. And by that, I mean thanks for the lesson!)
FYI baseball people: Grip a baseball or clench your fist and feel the ulnar collateral ligament area—tightened and flexed! Wouldn’t it make sense that with all that gripping of the baseball, there should be some balance in grip training with finger and wrist extension (the opposite of gripping), knowing there is a direct effect on that area!? We already know the throwing arm is out of balance and spend a great deal of time addressing balance—not necessarily a 50/50 balance—yet not one word about the grip. Why not the grip?
A study comparing fat grip resistance training with regular grip resistance training (Cummings et al., 2018) found “…that training with FG (fat grip) compared with normal diameter bars can signiﬁcantly increase both RT (resistance training; left hand grip strength) performance and golf driving performance (ball speed, carry, drive distance) in DI male golfers.”
Fat bar training note: Ratamess et al., 2007, concluded what most of us already know, “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.”
What’s your intent when using fat grip training? If it’s for grip training, good idea. At the same time, bar width will lighten your load, thereby sacrificing pulling strength and maybe pressing strength for grip. It’s a nonsensical proposition if you are trying to optimize pulling strength or hypertrophy by way of a given exercise. It’s like limiting squat loads because you want to do calf raises.
Even though the force transducers measuring grip tightness were built into a mechanical arm and wooden rackets were used (4.37” grips), the results were interesting (Elliot, 1982). Tighter grips “increased the reaction impulse and rebound velocity of the ball (balls were delivered by a ball machine; racket velocities were approximated to that of college-level baseline drives), particularly for off-center impacts.” No surprise given the amount of conflicting grip strength conclusions in sport. Grabiner et al. (1983) found in a primary conclusion, contrary to Elliot, “…that grip firmness plays no role in tennis other than pre- and post-impact implement control.” Smart et al. (2011) found grip strength significantly correlated to post-test serve velocity, but so did bench press, vertical jump height, squat, gender, and arm length.
Four other studies (Ulbricht et al., 2016; Girard et al., 2009; Genevois et al., 2013; Baiget et al., 2014) looking at serve velocity or physical parameters. Two did not include grip strength as an assessment and the other two gave no real recommendation of any kind for grip strength contribution to performance. To me this points to a lack of grip strength studies and a lack of interest or punctuation for grip strength.
My Anecdotal Experience, Hypotheses, and Common Sense
Hand size and strength play a role in sporting success, albeit not a crucial role. Think about it: The bigger the hand, the more coverage you’ll have “up the handle” on a bat and therefore better control of the bat head. These benefits would be obvious in racquet sports.
Strength aside, the control of the implement in these cases would be important. Bigger hands would mean more jersey to grab and hold, more gi to control, better wrist control, or holding a submission in wrestling (not the piledriver or throwing someone over the ropes). To anybody who’s done it, the more hand you can put on a football, basketball, baseball, or any ball for that matter—not to exclude a shot put, javelin, or disc—the better control and direction you might have of the object.
Gripping is a common, everyday thing. You could posit that reversing the action of gripping (opening the hand and fingers as wide as possible against resistance) makes total sense. We always talk about muscle balance in the legs, shoulder, and trunk, but I hardly ever hear of that discussion in relation to grip during all the grip hullabaloo. Putting an elastic band around the fingers and thumb and opening the hand against that resistance makes total physiological sense. So much so that if you’re saying grip strength is that important, then reverse grip movements should be on the workout sheet too!
There are times when grip strength, or at least maximum grip strength, is not needed. It’s important, but not always necessary. I know of programs spending up to 15 minutes of a 45-60-minute workout on grip strength. A coach has to shrewdly address committing 25% of a workout to grip, knowing that there are several other more important parameters most of the time. A well-rounded program includes grip strengthening—it’s called training. A coach can’t dismiss that. Research has proven it.A well-rounded program includes grip strengthening—it’s called training. A coach can’t dismiss that. Click To Tweet
My takeaway from my investigation is that the impact each finger has on grip strength is magnified when you look at the force produced over a range of gripping widths. Therefore, train the flexion and extension of the fingers through many ranges of motion!
After reading some 70 abstracts and studies, as I said in the second paragraph of this article, it’s pretty clear that it’s unclear how much gripping contributes to athletic or physical performance. Stronger people have stronger grips than weaker people; bigger people (body mass) have stronger grips than smaller people; older people have stronger grips than younger people. If you want to be able to hold heavy objects, lift heavy objects—this is common sense to anyone who has coached at least one month.
I only saw grip strength having predictive validity when it relates to wellness. Studies have shown that grip strength increases with grip strength training added to regular lifting. Studies have also shown that the added increase in grip strength did not improve performance. In fact, Layton et al. showed that in racquetball tournament play, there was no “significant or practical difference” between first place finishers and the remainder of the field.Research shows that grip strength is important, but not critical to athletic performance. Click To Tweet
Grip strength is shown to be important, but not critical to or predictive of athletic performance. There are plenty of correlates, but overall it appears as if grip strength is a by-product of other measures and qualities and not the other way around.
Abraldes, J.A., Canossa, S., Soares, S.M., Fernandes, R.J. & Garganta, J.M. “Relationship Between Hand Grip Strength and Shot Speed in Different Competitive Level Water Polo Players.” Center of Research, Education, Innovation and Intervention in Sport. 2014.
Amaral, J.F., Mancini, M. & Novo Júnior, J.M. “Comparison of three hand dynamometers in relation to the accuracy and precision of the measurements.” Brazilian Journal of Physical Therapy. 2012.
Amis, A. “Variation of finger forces in maximal isometric grasp tests on a range of cylinder diameters.” Journal of Biomedical Engineering. 1987.
Baiget, E., Fernandez-Fernandez, J., Iglesias, X., Vallejo, L. & Rodrıguez, F.A. “On-court endurance and performance testing in competitive male tennis players.” The Journal of Strength and Conditioning Research. 2014.
Cardenas-Sanchez, C., Sanchez-Delgado, G., Martinez-Tellez, B., Mora-Gonzalez, J., Löf, M., España-Romero, V., Ruiz, J.R. & Ortega, F.B. “Reliability and validity of different models of TKK hand dynamometers.” American Journal of Occupational Therapy. 2016.
Chiarlitti, N.A., Delisle-Houde, P., Reid, R.E.R., Kennedy, C. & Andersen, R.E. “The Importance of Body Composition in the National Hockey League Combine Physiologic Assessments.” The Journal of Strength and Conditioning Research. 2017.
Cooper, R., Kuh, D. & Hardy, R. “Objectively measured physical capability levels and mortality: systematic review and meta-analysis.” British Medical Journal. 2010.
Cronin, J., Lawton, T., Harris, N., Kilding, A. & McMaster, D.T. “A brief review of handgrip strength and sport performance.” The Journal of Strength and Conditioning Research. 2017.
Crossland, B.W., Hartman, J.E., Kilgore, J.L., Hartman, M.J. & Kaus, J.M. “Upper-body anthropometric and strength measures and their relationship to start time in elite luge athletes.” The Journal of Strength and Conditioning Research. 2011.
Cummings, P.M., Waldman, H.S., Krings, B.M., Smith, J.W. & McAllister, M.J. “Effects of fat grip training on muscular strength and driving performance in division I male golfers.” The Journal of Strength and Conditioning Research. 2018.
Da Silva, B., Marocolo, M., de Moura Simim, M.A., Rezende, F.N., Franchini, E. & da Mota, G.R. “Reliability in kimono grip strength tests and comparison between elite and non-elite Brazilian Jiu-Jitsu players.” 2012.
Derwin, J. “Effective Methods of Grip Strength Development.” NSCA COACH 2.3 | NSCA.COM.
Edgren, C.S., Radwin, R.G. & Irwin, C.B. “Grip force vectors for varying handle diameters and hand sizes.” Human Factors: The Journal of the Human Factors and Ergonomics Society. 2004.
Elliott, B. “Tennis: the influence of grip tightness on reaction impulse and rebound velocity.” Medicine & Science in Sports & Exercise. 1982.
España-Romero, V., Ortega, F.B., Vicente-Rodríguez, G., Artero, E.G., Rey, J.P. & Ruiz, J.R. “Elbow position affects handgrip strength in adolescents: validity and reliability of Jamar, DynEx, and TKK dynamometers.” The Journal of Strength and Conditioning Research. 2010.
Follmer, B., Dellagrana, R.A., Franchini, E. & Diefenthaeler, F. “Relationship of kimono grip strength tests with isokinetic parameters in jiu-jitsu athletes.” Revista Brasileira de Cineantropometria e Desempenho Humano. 2015.
Fry, A.C., Ciroslan, D., Fry, M.D., LeRoux, C.D., Schilling, B.K. & Chiu, L.Z. “Anthropometric and performance variables discriminating elite American junior men weightlifters.” The Journal of Strength and Conditioning Research. 2006.
Fry, A.C., Honnold, D., Hudy, A., Roberts, C., Gallagher, P.M., Vardiman, P.J. & Dellasega, C. “Relationships Between Muscular Strength and Batting Performances in Collegiate Baseball Athletes.” The Journal of Strength and Conditioning Research. 2011.
Gale, C.R., Martyn, C.N., Cooper, C. & Sayer A.A. “Grip strength, body composition, and mortality.” International Journal of Epidemiology. 2007.
Garcia Pallerés, J., López-Gullón, J.M., Torres-Bonete, M.D. & Izquierdo, M. “Physical fitness factors to predict female Olympic wrestling performance and sex differences.” The Journal of Strength and Conditioning Research. 2012.
Genevois, C., Frican, B., Creveaux, T., Hautier, C. & Rogowski, I. “Effects of two training protocols on the forehand drive performance in tennis.” The Journal of Strength and Conditioning Research. 2013.
Girard, O. & Millet, G.P. “Physical Determinants of Tennis Performance in Competitive Teenage Players.” The Journal of Strength and Conditioning Research. 2009.
Grabiner, M., Groppel, J. & Campbell, K. “Resultant tennis ball velocity as a function of off-center impact and grip firmness.” Medicine & Science in Sports & Exercise. 1983.
Hoffman, J.R., Vazquez, J., Pichardo, N. & Tenenbaum, G. “Anthropometric and performance comparisons in professional baseball players.” The Journal of Strength and Conditioning Research. 2009.
Jawan, L., Adnan, R., Sulaiman, N. & Ismail, S.I. “Efficacy of Handgrip Strength in Predicting Total Body Strength Among High Performance Athletes.” In Proceedings of the International Colloquium on Sports Science, Exercise, Engineering and Technology. 2014.
Kerr, A., Syddall, H.E., Cooper, C., Turner, G.F., Briggs, R.S. & Sayer, A.A. “Does admission grip strength predict length of stay in hospitalised older patients?” Age and Ageing. 2006.
Kohmura, Y., Aoki, K., Yoshigi, H., Sakuraba, K. & Yanagiya, T. “Developments of a baseball-specific battery of tests and a testing protocol for college baseball players.” The Journal of Strength and Conditioning Research. 2008.
Layton, J.S. & DeBeliso, M. “Is There a Relationship between Maximal Grip Strength and Racquetball Success? A Pilot Study.” Athens Journal of Sport. 2017.
LeWine, H. “Grip strength may provide clues to heart health.” Harvard Health Blog. Posted May 19, 2015, 12:11 pm, Updated September 08, 2016, 5:16 pm.
Mangine, G.T., Hoffman, J.R., Fragala, M.S., Vazquez, J., Krause, M.C., Gillett, J. & Pichardo, N. “Effect of age on anthropometric and physical performance measures in professional baseball players.” The Journal of Strength and Conditioning Research. 2013.
Pedão, S.T., Aguiar, S., Cunha, B.P. & de Freitas, P.B. “Grip and load force control and coordination in object manipulation during a night of sleep deprivation.” Sleep and Biological Rhythms. 2014.
Platzer, H.P., Raschner, C. & Patterson, C. “Performance -determining physiological factors in the luge start.” Journal of Sports Sciences. 2009.
Ploegmakers, J.J., Hepping, A.M., Geertzen, J.H., Bulstra, S.K. & Stevens, M. “Grip strength is strongly associated with height, weight and gender in childhood: a cross sectional study of 2241 children and adolescents providing reference values.” Journal of Physiotherapy. 2013.
Ratamess, N.A., Faigenbaum, A.D., Mangine, G.T., Hoffman, J.R. & Kang, J. “Acute muscular strength assessment using free weight bars of different thickness.” The Journal of Strength and Conditioning Research. 2007
Roberts, H.C., Denison, H.J., Martin, H.J., Patel, H.P., Syddall, H., Cooper, C., & Sayer, A.A. “A review of the measurement of grip strength in clinical and epidemiological studies: towards a standardised approach.” Age and Ageing. 2011.
Sayer, A.A., Syddall, H.E., Martin, H.J., Dennison, E.M., Anderson, F.H. & Cooper, C. “Falls, sarcopenia, and growth in early life: findings from the Hertfordshire cohort study.” American Journal of Epidemiology. 2006.
Smart, J., McCurdy, K., Miller, B. & Pankey, R. “The Effect of Core Training on Tennis Serve Velocity.” The Journal of Strength and Conditioning Research. 2011.
Spaniol, F. “Baseball Athletic Test: A Baseball-Speciﬁc Test Battery.” Strength and Conditioning Journal. 2009.
Su, C.Y., Lin, J.H., Chien, T.H., Cheng, K.F. & Sung, Y.T. “Grip strength in different positions of elbow and shoulder.” Archives of Physical Medicine and Rehabilitation. 1994.
Syddall, H.E., Martin, H.J., Harwood, R.H., Cooper, C. & Aihie Sayer, A. “The SF-36: a simple, effective measure of mobility-disability for epidemiological studies.” Journal of Nutrition, Health and Aging. 2009.
Szymanski, D.J. & DeRenne, C. “The Effects of Small Muscle Training on Baseball Hitting Performance: A Brief Review.” Strength and Conditioning Journal. 2010.
Szymanski, D.J., DeRenne, C. & Spaniol, F.J. “Contributing factors for increased bat swing velocity.” The Journal of Strength and Conditioning Research. 2009.
Szymanski, D.J., McIntyre, J.S., Szymanski, J.M., Molloy, J.M., Madsen, N.H. & Pascoe, D.D. “Effect of wrist and forearm training on linear bat-end, center of percussion, and hand velocities and on time to ball contact of high school baseball players.” The Journal of Strength and Conditioning Research. 2006.
Szymanski, D.J., Szymanski, J.M., Molloy, J.M. & Pascoe, D.D. “Effect of 12 weeks of wrist and forearm training on high school baseball players.” The Journal of Strength and Conditioning Research. 2004.
Szymanski, D.J., Szymanski, J.M., Schade, R.L., Bradford, T.J., McIntyre, J.S., DeRenne, C. & Madsen, N.H. “The relation between anthropometric and physiological variables and bat velocity of high school baseball players before and after 12 weeks of training.” The Journal of Strength and Conditioning Research. 2010.
Trosclair, D., Bellar, D., Judge, L.W., Smith, J., Mazerat, N. & Brignac, A. “Hand-Grip Strength as a Predictor of Muscular Strength and Endurance.” The Journal of Strength and Conditioning Research. 2011.
Ulbricht, A., Fernandez-Fernandez, J., Mendez-Villanueva, A. & Ferrauti, A. “Impact of ﬁtness characteristics on tennis performance in elite junior tennis players.” The Journal of Strength and Conditioning Research. 2016.
Watanabe, Y., Yamada, Y., Yoshida, T., Matsui, T., Seo, K., Azuma, Y., Hiramoto, M., Miura, Y., Fukushima, H., Shimazu, A., Eto, T., Saotome, H., Kida, N. & Morihara, T. “Relationship between physical fitness at the end of pre-season and the in-season game performance in Japanese female professional baseball players.” The Journal of Strength and Conditioning Research. 2017.
Yim, S.Y., Cho, J.R. & Lee, I.Y. “Normative Data and Developmental Characteristics of Hand Function for Elementary School Children in Suwon Area of Korea: Grip, Pinch and Dexterity Study.” Journal of Korean Medical Science. 2003.
Yingling, V.R., Webb, S., Inouye, C., O, J. & Sherwood, J. “Muscle power predicts bone strength in Division II athletes.” The Journal of Strength and Conditioning Research. Post Acceptance: August 29, 2017