With this entry I will be wrapping up my series on grip types; I hope this will help clearing a bit the always provocative issue of terminology, and understanding the pros and cons of each finger configuration. Without further ado, let’s start describing the open grip and the pinch grip.
Open hand grip
Depending on the authors, it is also known as slope grip (Schweizer, 2001, Quaine & Vigouroux, 2004; Roloff et al., 2006; Amca et al., 2012), open hand (Watts et al., 2008; Giles, Rhodes, & Taunton, 2006), hanging position (Schoffl et al. 2007; Schöffl et al., 2009) and extended grip (Fuss, Niegl, & 2012a).
There are several aspects that set this grip apart from the crimp grip:
1. Position of the fingers
The proximal interphalangeal joint (PIP) is more extended while the distal (DIP) joint is flexed: Less than 30º flexion in the former and 50º to 70º in the latter (figure 2).
2. Relative force applied by the flexor digitorum profundus (FDP) compared to the flexor digitorum superficialis (FDS)
The works by Vigouroux et al. (2006) and Schweizer & Hudek (2011) showed that using the crimp grip on holds less than 1-phalanx deep the applied force ratio between FDP and FDS was 1.75:1; the picture is not that clear in the case of the slope grip where the results of the mentioned studies seem to go in different directions. We can only go as far as supposing that the contribution of both muscles is more balanced in the slope grip.
Interestingly, the flexor digitorum superficialis exerts more force than expected if we think that it is inserted at the second phalanx and so has no effect on the DIP flexion that is characteristic of the slope grip. A possible explanation could be its role in stabilizing the PIP to avoid a phenomenon called “swan neck” (Schweizer & Hudek, 2011) (figure 3).
Even though these findings help us to understand the characteristics of each grip type, we must be cautious when interpreting them. The authors themselves acknowledged the limitations of their study due to the fact that they tested one finger at a time, which does not take into account the influence of coactivation of the extensors and the intrinsic muscles of the hand. They proposed further studies to evaluate this aspect by using deeper holds and measuring forces for the hand as a whole as well as for each finger.
3. Increased efficiency on one finger pockets
Using the slope grip in a one-finger pocket we apply 20% more force at the fingertip than with the half crimp for a given muscle force. One reason for this could be that it is easier, in terms of mechanical advantage, to maintain the flexion at the DIP than at the PIP, because in the half crimp the resistance arm is longer (Schweizer, 2001) (figure 4)
4. Better efficacy on various kinds of hold
4.1.1. Holds deeper than one phalanx and a half
Amca et al., (2012) and Schweizer & Hudek (2011) showed that using this grip the amount of force applied on a 40mm hold was significantly higher than with the half-crimp and full-crimp. These authors suggest that the position of the fingers promotes an optimal contact and better friction over the contact area. By the way, the terms chisel or dragging-grip highlight this property of maximizing friction as we try to do on slopers and pockets to the detriment of our calluses, that usually get squeezed (figure 5).
4.1.2. Rounded lip pockets. When this grip type is used on pockets it is also called pocket grip.
4.1.3. Sloped floor pockets, flat volumes, sloping holds.
Although the positions of the fingers are very similar, these holds require a way of applying force peculiar enough to warrant a more detailed overview.
Slightly positive or coarse holds, even if they are round, allow us to take advantage of friction by “relaxing” the finger a bit and letting the lip of the hold sink a bit in our flesh. When there is no lip, we can’t rely on that trick, neither we can pull in the anteroposterior direction and we need to resort to a different way of maximizing our contact area for as long as we can.
a) Adapting our hand to the shape of the hold, like trying to “cover” it. On very flat slopers (like those typical of Fontainebleau) our fingers will be nearly extended, perhaps with a slight flexion both at PIP and DIP of the center ones: ring and middle fingers (figure 6). Meanwhile, an open grip or dragging on a positive of flat edge the flexion at the DIP will be noticeably more pronounced, close to 50º.
b) Friction is boosted by “compressing” instead of dragging. Force tends to be applied constantly, right from the moment of contact; this is different from other holds, where we allow the fingers some “give” to mold into the shape of the hold before committing to a firmer, isometric grip. Here it is essential to keep a consistent amount of pressure, which calls for extra focus while we move our feet or when we are tired.
c) Our position in space becomes tightly linked to friction, because it is necessary to place our body mass below the hold as much as possible while using the intrinsic muscles (specially the interossei and lumbricals muscles) and extrinsic muscles of the hand and wrist (specially the flexor carpi radialis and extensor carpi radialis apart from FSD and PDP like in the rest of grips), arm, shoulder and chest to “push” the hold perpendicularly (normal force), especially with the distal phalanx. The two last details were measured by Fuss & Niegl, (2008, 2012b) and Fuss et al (2014) by looking at competition climbers of different levels (above 20th and below 50th in World Cup events; beware: the sample size was small). Their conclusion was that the highest level participants achieved higher friction and displayed a shorter contact time (they reached their peak force and were able to release the hold sooner) (figure 7).
It is remarkable how both on slopers and tiny holds the most force is applied at the fingertips. Whether we can draw any conclusions from this fact that can be relevant to our training is a matter worth some thought.
d) Timing and pulling strength become important factors: it is common to stall briefly when first contacting a sloper, sometimes because there is so much shifting going on from fingertips to center of mass and toes, which requires awareness. But at the same time we usually can’t afford to spend time before pulling and reaching for the next hold before losing contact with the sloper. In other words: a positive edge or pocket gives us some choice of speed; it also permits shifts in wrist position to modify our reach, allowing a greater contribution of the muscles in the back and even pushing with our triceps in the final phase. By contrast, a big flat surface prevents us from pulling towards us in the same fashion because there is no lip, and we are often forced to lunge while exerting a lot of tension with our arm; in fact, pulling strength is not vital at first contact, but it makes all the difference very soon, when the time comes to reach with our free hand. There is also the extra variable of slopers being particularly unforgiving with sweaty skin; extending contact time can build up enough moisture to thwart our efforts.
At this point it will not come as a surprise to you the link between performance on slopers and climbing experience (perceptive-motor repertoire), strength level (absolute hand, arm and chest strength) and technical skills (like keeping a steady grip while while moving our feet).
5. Association to injury
The fact that this finger position transfers 36 times less tension to the A2 pulley and 4 times less to the A4 than crimping (Vigouroux et al., 2006), leads us to suggest this grip type can be healthier for said structures. As such, it would be a sensible choice when there are symptoms of overload or when recovering from injures of the pulleys and/or tendons. In this case it would be helpful to apply taping in order to limit crimping and flexion of the PIP.
However, this is not a completely safe grip type (there’s no such thing as total security) and it could be related to injuries of the myotendinous junction of the fingers’ flexor muscles and of the lumbrical and interossei. In the first case the mechanism would be peak force being exerted with both muscle and tendon at maximum extension; the other two can occur by the contrast between the flexion that the free fingers can adopt when pulling off a one- or two-finger pocket and the extension of the acting fingers (Schweizer, 2003) (figure 8)
When pinching we take advantage of our opposable thumb to squeeze the hold between our fingers. This confers some special characteristics to this way of gripping:
- It relies more on absolute hand strength. We need to firmly oppose the thumb to 'crush' the hold and generate enough friction on all the fingers; while in other grip types, the force against the hold surface is usually provided by gravity (apart from finger strength, of course).
- The position of the body has a big impact on efficiency: aligning the elbow and shoulder or, if possible, rolling the hip, flexing the elbow to 90º and bringing the waist close to the hold. Transferring this to a training setting means doing exercises where our wrist is in a natural position (15º-30º extension, Irmhan, 2001), the forearm in a neutral position (neither supine or prone) with our thumb pointing 'upwards' (McGorry and Lin, 2007) and our arms in front of us. If we added to this combination an ideal shoulder flexion of 45º-135º, we would be in the best position to apply the maximum force using this grip type (Kong et col., 2011)
- While in the crimp grip the most solicited finger is the index finger, and the middle finger is the one that bears the most load in the open hand, open crimp and power grip (like grabbing a good rounded tufa) (Quaine et col., 2004; Fuss and Niegl, 2012a), in a 'purer' pinch grip, according to ergonomics studies, apart from the thumb it is the index finger the one that does the most work, at 35% of the force exerted by the whole hand (Radwin and Oh, 1992).
- The thumb is controlled by the combined action of 8 different muscles, which translates into a freedom of movement that does not go to waste in climbing. Together with the flexor and extensor muscles of the fingers and wrist they can manage a wide gamut of hold shapes, from the comfortably wide (around 8 cm) and round represented by the ideal tufa to the narrow (less than 6 cm), one-phalanx deep that require flexing the thumb and crimping; from the very wide, open-hand style to the dreaded, negative incut… On a side note, it’s not uncommon to also find ourselves feeling for some feature with our thumb when pulling off some hold that we would not consider a pinch if only it were a bit bigger.
- The mentioned variety of hand actions translates into a number of variables that can be taken advantage of in order to adjust the intensity and quality of training: depth, orientation (vertical, diagonal), profile (incut, flat, negative) and width.
Summing up, pinches will improve not only our hand, shoulder or chest strength, but also our feet placement, body position and technique in general, something that they have in common with slopers. Climbing efficiently on pinches forces us to place our center of mass in a different and more subtle fashion than what is needed for more 'stable' holds like edges and pockets.
More info about pinch strength on: Training Pinch Grip Strength for Climbing. Are dead hangs the right way to do it?
NOW THAT WE HAVE REACHED THE END of our journey through the grip types, we arrive to the great question that, as is often the case, should spawn multiple others:
If we know that holds come in so many shapes that result in several grip types; and having in mind that the effects of isometric training are specific to the position that is being effectively used while training (Gardner, 1963), should we have to train separately each one of them? Should I have to hang off every possible grip type?
Theoretically the answer is yes, but we are already used to things being more complicated that they seem at first sight, and the answer would depend on:
Climbing spot or route you are training for
Available training devices
Level and training experience
Ok, If I don’t have the kind of time or equipment to do that, which grip should I choose? Is it better to opt for the one that best transfers to all the rest or to focus on the most specific of my project or favorite crag? Does crimping strength transfer to open hand or pinch? And what about slopers, with their host of peculiarities? Does it make any sense to do dead-hangs on slopers?
I will be answering these questions in the next articles to come. Meanwhile, I leave them here so that we can reflect on them.
More about climbing training on: www.en-eva-lopez.blogspot.com
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Amca, A. M., Vigouroux, L., Aritan, S., & Berton, E. (2012). Effect of hold depth and grip technique on maximal finger forces in rock climbing. Journal of Sports Sciences, 30(7), 37–41.
Fuss, F. K., & Niegl, G. (2008). Instrumented climbing holds and performance analysis in sport climbing. Sports Technology, 1(6), 301–313.
Fuss, F. K., & Niegl, G. (2012a). Finger load distribution in different types of climbing grips. Sports Tecnology, 4 (3-4), 151–155.
Fuss, F. K., & Niegl, G. (2012b). The importance of friction between hand and hold in rock climbing. Sports Technology, 5 (December), 90–99.
Fuss, F. K., Weizman, Y., Burr, L., & Niegl, G. (2014). Assessment of grip difficulty of a smart climbing hold with increasing slope and decreasing depth. Sports Technology, (April 2014), 37–41.
Gardner, G. W. (1963). Specificity of strength changes of the exercised and non exercised limb following isometric training. Res. Q. Ex- Erc. Sport, (34), 98–101.
Giles, L. V, Rhodes, E. C., & Taunton, J. E. (2006). The physiology of rock climbing. Sports Medicine (Auckland, N.Z.), 36(6), 529–45.
Imrhan, S.N. (2001). Handgrip Characteristics and Strength. In W. Karwowski (ed.): International Encyclopedia of Ergonomics and Human Factors, Taylor and Francis, Vol. 1, pp. 252-254.
Imrhan, S.N. (1999). Hand grasping, finger pinching and squeezing. Biomechanics in ergonomics, 97.
Kong Y., Song Y., y Jung M., Lee I. (2011). Effects of hand position on maximum grip strength and discomfort. HFESA 47th Annual Conference 2011. Ergonomics Australia - Special Edition.
López Rivera, E. (2012). Training Pinch Grip Strength for Climbing. Are dead hangs the right way to do it?, “Eva López, Ph.D. Climbing Coaching based on Science and Experience" [on-line]. 7 February 2013. Available on: https://en-eva-lopez.blogspot.com.es/2013/02/training-pinch-strength-for-climbing.html
McGorry, R.V. (2007). Power grip strength as a function of tool handle orientation and location. Ergonomics. 50 (9), 1392–1403
Quaine, F., & Vigouroux, L. (2004). Maximal resultant four fingertip force and fatigue of the extrinsic muscles of the hand in different sport climbing finger grips. International Journal of Sports Medicine, 25(8), 634–637.
Radwin R.G. y Oh S. (1992). External fingers forces in submaximal five-finger static pinch prehension. Ergonomics, 35(3), 275-288
Roloff, I., Schöffl, V. R., Vigouroux, L., & Quaine, F. (2006). Biomechanical model for the determination of the forces acting on the finger pulley system. Journal of Biomechanics, 39(5), 915–923.
Schoffl, I., Einwag, F., Strecker, W., Hennig, F., & Schoffl, V. (2007). Impact of taping after finger flexor tendon pulley ruptures in rock climbers. Journal of Applied Biomechanics, 23(1), 52–62.
Schöffl, I., Oppelt, K., Jüngert, J., Schweizer, A., Neuhuber, W., & Schöffl, V. (2009). The influence of the crimp and slope grip position on the finger pulley system. Journal of Biomechanics, 42(13), 2183–2187.
Schweizer, A. (2001). Biomechanical properties of the grip position in rock climbers. Journal of Biomechanics, (34), 217–223.
Schweizer, A. (2003). Lumbrical tears in rock climbers. Journal of Hand Surgery, 28 B(2), 187–189.
Schweizer, A., & Hudek, R. (2011). Kinetics of Crimp and Slope Grip in Rock Climbing. Journal of Applied Biomechanics, 27(2), 116–121.
Vigouroux, L. (2006). Fingertip force and electromyography of finger flexor muscles during a prolonged intermittent exercise in elite climbers and sedentary individuals. Jounal of Sports Sciences, 24(2), 181–186.
Vigouroux, L., Quaine, F., Labarre-Vila, A., & Moutet, F. (2006). Estimation of finger muscle tendon tensions and pulley forces during specific sport-climbing grip techniques. Journal of Biomechanics, 39(14), 2583–2592.
Watts, P. B., Jensen, R. L., Gannon, E., Kobeinia, R., Maynard, J., & Sansom, J. (2008). Forearm EMG during rock climbing differs from emg during hand grip dynamometry. International Journal of Exercise Science, 1(1), 4–13.