Range of Motion: How to Care for Your Dog's Joints

by Susan E. Davis, PT

Every joint in a dog’s body is designed for movement and has a normal amount of scope it moves through. This is termed as “Range of Motion” or ROM of a joint. There are documented values, measured in degrees, which are the standards optimal for each of the joints. Dogs function best when their ROM is within these normal values. However when illness, surgery or injury take place, the dog may be less active and over time their joints become stiff, losing normal range of motion. Other times, due to trauma, the joint might be dislocated and too loose, unstable. During a Veterinary or PT evaluation, the joints are examined and range of motion is measured with a goniometer. Those joints determined to be tight, and not in the “normal” value range, will be identified and may benefit from specific ROM exercises. Joints move in various ways, such as the shoulder and hip which are “multi-axial”, or the elbow and knee (stifle) which are “hinge” joints.

Multi-axial means that the shoulders and hips move in 3 different planes of movement as well as in 6 directions:

1. Extension in which the arm moves forward and up toward the head.
2. Flexion in which the arm moves in a backward direction toward the tail.
3. Abduction the arm moves away from the body, out to the side.
4. Adduction the arm moves close to and across the body.
5. Rotation the shoulder turns inward and outward to achieve Internal and External rotation.

The Stifle and Elbow, being hinge joints, move in only 1 plane, with 2 directions:

1. Flexion or bending
2. Extension or straightening

The Carpus (wrist) joint moves into 4 directions:

1. Flexion or bending down with the paw tucked in toward the body.
2. Extension or bending up and back as if the paw is in a wave position.
3. Deviation, where the paw moves from side to side. The Hip moves similarly to the shoulder except the terminology changes slightly. Flexion is where the thigh moves forward and toward the stomach and ribs (knee to chest).
4. Extension, where the thigh moves in a backward direction toward the rump.

The hock (ankle) joint bends in several directions, but the 2 main directions are:

1. Cranial Flexion: Toes up direction, where the paw bends toward the head
2. Plantar Flexion: Toes pointed direction, where the paw points away from the body toward the tail

When a Veterinarian or Physical Therapist uses a goniometer to measure your dog’s ROM, they will document the result, can advise you of the number and explain how it relates to normal values.

For example, if I am evaluating a dog that just had sutures removed after CCL surgery, I will measure the degrees of stifle flexion. A typical result might be 15 degrees. I will advise the client that normal values for stifle flexion are 42 degrees, and the current measurement is about 35 % of normal. I would also assure them of what to expect in terms of recovery and how likely the dog is to regain full range, in what time frame, etc.

Abnormal range of motion is characterized by being either too tight, "Hypo mobile,” or too loose, "Hypermobile.” In cases of hypermobility, the joint needs to be rested and restricted from excessive motion by use of splints or wraps. With hypo mobility, joints need exercise in order to gain flexibility and movement. Range of motion exercises will be employed, where the joints and surrounding muscles are moved through their available ranges. This movement may be passive, active or active-assisted.

Your Dog's Range of Motion

Passive range of motion exercises are performed by external force (therapist’s hands, mechanical device) and without any participation by the animal. This is used when the animal patient is unable to move joints on their own or if self-movement is painful or detrimental. Proper technique is very important when Passive ROM is performed. The therapist must cradle and support the limb to avoid jarring or twisting stress on joints. The exercise should be smooth, slow and steady, with the dog relaxed and comfortable. A dog owner who is willing to learn can be taught to perform basic PROM at home, but they should be carefully instructed and supervised several times. Written instructions should be given or video of the exercise recorded for the owner. Passive ROM exercises are usually performed for 5-10 repetitions, 2-3 times per day. A dog owner who is uncomfortable doing this type of joint motion should be open and honest about it and never forced to perform PROM on their pet. It is better to spend the time and money having a professional provide the service than to have it done incorrectly and risk injury. There is no shame in admitting to feeling “queasy” about this. The only shame is to neglect having passive ROM exercises done when they are needed.

The other 2 types of ROM are Active-Assisted, and Active.

Active-assisted ROM occurs when the therapist guides the dog’s joint motion and the dog’s muscles assist to a partial degree.

Active ROM is achieved by full muscle contraction by the animal. Placing a treat or toy in a certain position can stimulate the animal to move their limb on their own, through ranges of motion. Also, walking in sand or water, over rails or through a tunnel can achieve active movement through a joint’s range of motion.

All ROM exercises are performed up to the limit of a joint’s available range, whether done by passive, active-assisted, or active method. Additional pressure applied to the end of this range is called stretching.