Get a Grip!

Muscles of the thumb

Some of the thumb muscles belong to the extrinsic forearm muscles mentioned above. However, the intrinsic muscles include:

Thenar eminence (see Figure 5)

1. Opponens pollicus
2. Abductor pollicus brevis
3. Flexor pollicus brevis

Hypothenar eminence (see Figure 6)

1. Flexor digiti minimi brevis
2. Abductor digiti minimi
3. Opponens digiti minimi

Finally, in the hand we also have:

1. Four lumbrical muscles
2. The dorsal and palmar interossei
3. Adductor pollicus
4. Palmaris brevis

Measuring grip strength

Grip strength can be measured using a handheld dynamometer (see Figure 7). A typical protocol is to measure 5-second maximal contractions with the arm in three different positions: neutral, 90⁰ abduction, and 90⁰ abduction with 90⁰ external rotation. The wrist is kept in neutral and the elbow at 90⁰ flexion in all positions. Subjects should stand with the feet approximately shoulder width apart, with a wall behind to add stability and to prevent trunk rotation and help maintain arm position. Usually, three measurements are taken and the average of the three is used. Pincer strength (Figure 7) is measured with a pinch meter and is a measure of individual finger to thumb strength usually measured with the fingers in relative extension.

Improving grip strength

There are numerous types of grip positions that we can use when training. The most common grip is a cylindrical grip (which is part of the power grip series). A cylindrical grip is where you clasp your hands around a barbell or a dumbbell to a point where the first pad of the thumb can be placed over the index and ring finger. This is the most common grip variation in typical strength training using standard barbells and dumbbells.

Common ways to develop this cylindrical grip strength are exercises such as:

• Deadlift holds
• Milk can carries (strongman exercise)
• Hanging chin up with a closed grip (thumb opposing the index finger)
• Towel chin ups with a hold

The problem with this grip is that while it can build a lot of strength, sometimes this strength doesn’t cross over into other positions/environments where grip is required.

Battling ropes

The ‘battling ropes’ is an effective training tool to develop grip strength, primarily through the strongman pulling exercises performed across all three planes of motion (see Figures 8-15). Additionally, the different grip positions affect the way grip strength is developed - i.e. neutral grip and the classical overhand or pronated grip.

There are numerous muscles involved in movement of the forearm and hand (see above), with many of these involved in gripping activities like strongman pulls. Other positive crossovers relate to how strongman pulls can help facilitate stronger lifts - e.g. barbell deadlifts and pull-ups, where often it is the grip muscles that fail before the (larger) target muscles. There are also benefits for recreational activities like rock climbing, wrestling, tennis, and golf, all of which need strong flexor muscles whilst also maintaining good stability of the extensor muscles.

Developing grip in training can produce massive benefits in everyday life and sport. For example, shaking somebody’s hand you may notice that the power in the grip is predominantly from the thumb, index and middle finger. You may not notice that the ring and pinky finger don’t do too much work at all. In this scenario, we find someone is more prone to radial deviation (where the thumb is brought towards the inside of the elbow). This can lead to dysfunctions such as medial epicondylitis.

Powerbags and the Hook grip

When power bags are used in training, the benefit is the strap that can be used to grip in all a ‘hook’ grip (see Figure 14). This has a huge impact on the flexor digitorum muscles in the forearm. When the pollicis muscles/tendons (or the muscles involved with the thumb) are taken omitted from the grip action, there is greater variability as to how the upper arm and shoulder joint is utilised.

Other grips

• Spherical grip - this is similar to a cylindrical grip, but the object is thicker, so the thumb cannot reach the index and middle finger. With this grip, the whole kinetic chain from fingers through to the shoulder changes, and many people will feel much weaker.
• Lateral prehesion grip - an example of this is the use of Kettlebells, where the bell is held overhead with open hand positions (see Figure 15). In this grip, the adductor pollicis muscle of the thumb is drawn in towards the index finger, creating tension to keep that kettlebell in position. This grip position can also be seen can be seen in the overhead position in the kettlebell snatch and also in the starting position when performing the ‘Turkish get up’ exercise.

Pincer grip strength

Pincer grip positions usually involve the fingers being kept in some degree of extension (straight fingers). The muscles used in this grip sequence usually eliminate the strong extrinsic finger flexors and require more intrinsic muscle action such as the lumbricals. Due the extension of the fingers in these positions, the strong finger flexors need a position of active tension to effectively work. Therefore, it is common to see this grip posture involving 10-20 degrees of wrist extension. The wrist extensor muscles are therefore utilised to hold this wrist extensor position. A classic way to develop this pincer grip is by performing a ‘plate pinch’ (see Figure 16) for a specified time. The variations to a ‘plate pinch’ are:

1. Number of plates to make a thicker plate or thinner plate.
2. Holding the plates by the side or in front. This will change scapular stability posture.
3. Plates with ridges vs smooth plates (changes the coefficient of friction).

Summary

Grip strength is not only a fundamental component of successful skill execution and performances of strength ‘feats’ in sport, it is also linked to rotator cuff and shoulder pathologies. Therefore, actively training grip strength components can help as part of a strength and conditioning program - as well as in rehabilitation programs.

There are a host of muscles that contribute to a strong and powerful grip. Overall strength can be easily measured with commercial grip and pincer strength dynamometers. Many alternative methods of grip strength training exist such as barbells, dumbbells, Kettlebells, Ropes and plates.

Guest authors:

Tarek Michael Chouja is a strength coach and international course presenter in the fitness industry with 15 years experience. Tarek is the co-founder of the Functional Training Institute, which educates trainers and coaches worldwide.

Nathan Quinn is an exercise scientist working across numerous health sectors, winning the OH&S award for his work with Fairfax Media, writing and delivery numerous courses for Body-Brain Integration, Functional Training Institute and PTAGlobal.  Nathan also runs the Mindset & Performance Coach podcast on iTunes.

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