Home | Musicians' Health | Anatomy/Biomechanics | Piano Teaching | Richard Beauchamp

OUR ANATOMICAL DIFFERENCES

Richard Beauchamp

This is the outline of a talk given to EPTA in 1999, attempting to show why we should not treat all pupils alike, or expect them to achieve the same results with the same technical methods.

CONTENTS

Muscles in the arm

Flexor digitorum superficialis

Flexor digitorum profundus

Flexor pollicis longus

Extensor digitorum

Extensor digiti minimi

Extensor indicis

Extensor pollicis brevis

Palmaris longus

One of the most variable of muscles.

Much of the above information about the Palmaris Longus has been quoted from Quain's "Elements of Anatomy" and from Koo's and Roberts' paper "The Palmaris Longus Tendon".

[Contents]

Intrinsic muscles of the thumb (Thenar muscles)

Abductor pollicis brevis

Opponens pollicis

Flexor pollicis brevis

Adductor pollicis

Hypothenar muscles

Palmaris brevis

Abductor digiti minimi

Flexor digiti minimi brevis

Opponens digiti minimi

The other intrinsic muscles

Dorsal interossei

Palmar interossei

They contribute strongly to MCP flexion and interphalangeal extension.

Lumbrical muscles

Variations are common (45% according to Froment in 1846).

The lumbrical most frequently affected by double insertion is that of the ring finger (15% - 43% of cases). The distal insertion of the lumbrical can be seen on the ulnar side of the finger. Lumbrical muscles extended up the forearm easily produce a carpal tunnel syndrome. According to Kopsch (1898) and Reinhardt (1902) the classical arrangement of lumbricals occurs in only 39% of cases.

Lumbricals alter the balance between flexors and extensors and are important proprioceptors. the 1st lumbrical has approximately 50 neuromuscular spindles for a weight of about 3 grams.

[Contents]

The fingers

Index finger

Intrinsic muscles are normally independent, but in 1 in 10 cases are limited by:

The FDP tendon of the index finger:

The Extensor Indicis makes it possible to point this finger when the rest of the hand is in a fist. (Hence the name "index") Use of this muscle can help to lift the medius when the ring finger is flexed, thus limiting the tension between the ED connecting tendons for the medius and ring fingers.

Medius

Highly interdependent because of tendinous connections of ED tendons on back of hand, FDP connections, lack of differentiation in muscular mass of FDP, joint origins of 3rd lumbrical.

Full extension of medius limits DIP flexion in ring finger in 41% and in little finger in 11%.

(Try full extension test on DIP flexion in other fingers. Do this with great care, and do not force!)

Apparent flexion of DIP's in other fingers can be achieved by hyper extending them at the MCP, but this causes tension in the hand (Another danger of flexed finger tips?)

Ring finger

Similar to above, but exacerbated by having ED and FDP connections on both sides as well as sharing the common origins of both 3rd and fourth lumbricals.

Little finger

EDM makes it possible to point the little finger independently of the others, but this tendon is sometimes fused with the ED tendon and/or connected to it, or absent. Its ED tendon itself is usually only a slip branching off the tendon for the ring finger.

Raising the little finger with EDM can be a help in lifting the ring finger when the medius is flexed, as the ring finger is raised mainly by the web connection between it and the little finger, with some participation of the ED connecting tendons, and therefore communicates no tension to the other fingers. This, however, is no help at all if the EDM is absent or joined/fused to its ED tendon. It is interesting to watch the medius being helped by the EI and the ring finger being helped by the EDM in a trill with these two fingers.

The common habit of curling the little finger is a way of making the FDP act as a limiter for the other fingers (forcing them to flex slightly as they are raised and allowing them to open out as they descend) as well as aiding in the lifting of the ring finger. A pronounced curling of the little finger may be needed to achieve the right degree of limitation to the medius as the effect is conveyed across two FDP tendons. This technique is often observed in trills between the index and middle fingers. It may be unnecessary to create a limit to extension if the natural tonus of the FDP is sufficient to do so passively.


[Contents]

All piano teachers please memorise the following quote!

"Extrinsic muscles are said to be strong, pluriarticular, little differentiated motors, supplying mainly the force required for common power movements, without real precision. The short intrinsic muscles are said to be essentially the motors of fine movements."

- Marius Fahrer.



Sources

Gray's Anatomy.
Churchill Livingstone, 1995
Tubiana. R. Examination of the Hand and Upper Limb.
W. B. Saunders, 1984.
Fahrer. M. Interdependent and Independent Actions of the Fingers.
-from "The Hand" by Raoul Tubiana.
Harcourt.
Zancolli and Cozzi. Atlas of Surgical Anatomy of the Hand.
Churchill Livingstone, 1992.
Koo. C. C. and Roberts. A. H. N. The Palmaris Longus Tendon.
Journal of Hand Surgery (British and European Volume, 1997) 22B: 1: 138 - 139.
Quain's Elements of Anatomy, Vol IV Part II, Myology by T. H. Bryce.
Longmans, Green and Co. 1923.


©Copyright Richard Beauchamp 1999
Disclaimer
Valid XHTML 1.0!


Back to top | Home | Musicians' Health | Anatomy/Biomechanics | Piano Teaching | Richard Beauchamp