Muscle Length

Question 1

Differences between Joint ROM & Muscle Length

Answer 1

Both are expressed in degrees
If a muscle crosses only one joint, the measurement of range of joint motion and range of muscle length will be the same
If a muscle crosses more than one joint, you may need to allow the muscle to be slack over one joint to determine full joint ROM in other
Ex. Hip flexion - we flex the knee to allow the hamstring to be slack and permit full hip ROM

Question 2

What are muscle length tests?

Answer 2

Movements that increase the distance between the muscle origin and insertion to determine whether the range of motion is normal, limited, or excessive

Muscles that are excessive in length are usually weak and allow adaptive shortening of opposing muscles

Muscles that are too short are usually strong and maintain opposing muscles in a lengthened position

Question 3

Muscle Length Testing

Answer 3

This procedure is used to determine if the muscle length is:

Limited or short = too short to permit normal range of motion.
(Contracture - when there is a marked loss of ROM)

Excessive = stretched and long, allowing too much range of motion

Tight can mean short or taut (applied either to a short or a stretched mm)

Question 4

Contractile & Inert tissue

Answer 4

When putting a stretch when length testing a muscle, you are also putting tension on the tendons and bony attachments
Ask the client where they feel the tension

Nervous tissue and their associated sheths can be stretched or pinched as well.
A nerve stretch might feel different from a muscle stretch to the client

Question 5

PASSIVE INSUFFICIENCY

(multi-joint muscles)

Answer 5

Shortness of a two-joint (or multi-joint) muscle, when it is not allowing normal elongation over both joints simultaneously

Ex. hamstrings - both hip flexion and knee extension cannot be fully reached at the same time

Question 6

ACTIVE INSUFFICIENCY

(multi-joint muscles)

Answer 6

The inability of a multi-joint muscles to generate an effective force when placed in a fully shortened position

Ex. Maximal shoulder flexion cannot be achieved simultaneously with maximal elbow flexion due to the shortening of the Biceps Brachii.

Question 7

Shortness

Answer 7

Myofascial hypomobility may be caused from adaptive shortening or hypertonicity in the muscles or from post traumatic adhesions or scarring

Adaptive shortening is tightness that results from the muscle remaining in a shortened position (Ex. a wheelchair client with short hip flexors)

Question 8

Excessive length

Answer 8

Some people are naturally more flexible, and does not always mean there is anything pathological going on

With excessive length, the joint may be unstable. Always go slow with passive movements

Stretch weakness or Positional weakness results from muscles remaining in an elongated position