The recorded webinar Understanding and Improving Engagement and Collection focuses on the anatomy of the hindlimb. The main driving forces of your horse is provided by the muscles of the hindquarters and the upper hind limb. Impulsion is pushing power – the thrust that’s produced when energy created in the hindlimb is converted to forward movement.
Impulsion and collection are needed in varying degrees in all disciplines not just dressage. For example, when your horse jumps it’s the contained power that allows him to propel himself over an obstacle.
To gain a better understanding of how your horse creates impulsion and collection having knowledge of the anatomy of the hindlimb and how he moves is key. With this knowledge you'll be able to train him to perform at his best.
In this blog we'll look at the bones of the hindlegs and muscles of the hindquarters to give you a clearer insight into the world of impulsion and collection.
The Engine
The hindlegs are the power house of your horse. The function of the limbs is collectively referred to as the appendicular skeleton is to support your horse’s weight, to propel him forwards and help to maintain his balance.
The gluteals are the muscles that give the hindquarters their powerful rounded appearance. They provide forward propulsion and strength. These muscles lie on top of and behind the hip joint. There are three parts to the gluteals:
Gluteal superficialis – mainly responsible for flexing the hip
Gluteal medium – the biggest of the group and is responsible for hip extension
Gluteal profundus (deep gluteal) – mainly responsible for abducting the thigh
The hamstrings run down the back of the hind leg from the sacrum, the first few tail vertebrae and the pelvis. They merge to become the achilles tendon that attaches to the point of hock.
The hamstring group is made up of:
Biceps femoris
Semi-tendinosus
Semi-membranosus
These play a major role in propelling your horse forward. They extend and stabilise the hip joint, extend and flex the hock and stifle and allow the limbs to adduct and abduct.
Now, let’s take a closer look at the bones from hip to hock.
Hip Joint
This is situated deep within the hindquarter muscles. It’s location is often confused with the false hip – the bony protrusion on the side of the pelvis. The hip joint is where the hind limb attaches to the pelvis. As a ball and socket joint, the hip has a complete range of movement – the accessory ligament limits the leg moving up and away from the body.
Femur (Thigh bone)
A long bone that’s adapted for the attachment of the strong hindquarter muscles – it lies between the hip and hinge joint of the stifle.
It’s one of the strongest and heaviest bones in your horse’s body.
Stifle joint
Equivalent to your knee, the stifle joint forms the hinge between the femur and tibia. Concussion is absorbed through fibrocartilaginous pads within the ligaments.
Tibia (Shin bone)
The tibia lies between the stifle and hock and its main function is to provide an area for muscle and ligament attachment – the most important one being the deep digital flexor tendon.
The Hock
Equivalent to your ankle bone, the hock is a hinge joint made up of three rows of tarsal bones. The bony prominence is called the point of hock and is the equivalent to your heel. A complex arrangement of muscles, ligament and tendons enables the hock to work quickly and rhythmically.
The hock and stifle work simultaneously – the hock absorbs concussion and withstands the propulsive forces generated within the hind limb.
What is Impulsion?
When you horse is working with impulsion, he pushes off to move powerfully and energetically forward. Impulsion is not to be confused with speed – the Germans use the phrase ‘swung’, meaning – moving with a spring in the step and swing through the body. The greater the impulsion, the longer the moment of suspension.
Your horse will only have impulsion if his hindlegs are engaged and his back supple, allowing the power to come through from behind. Impulsion maximises your horse’s natural athleticism making his paces light, expressive and elastic. This power is required when you ask your horse to perform movements that need a high level of collection.
A good attitude is essential for impulsion – your horse needs to be fit, keen and energetic. A horse that’s bored or slow will not move with impulsion.
Vary your horse’s work – do activities he enjoys such as hacking, hill work and jumping. This will encourage him to move with impulsion.
Moving on to Collection
True collection requires balance, energy, impulsion, correct posture, skeletal maturity and well-conditioned muscles. This journey to collection begins as soon as you start training your horse. Collection is the culmination of the scales of training and requires your horse to lower and take more weight on to his hindquarters whilst shortening his frame and lifting the forehand.
Collection is a gradual process which takes correct training, time and patience. Developing collections is progressive and is relative to your horse’s age, level of training and his musculoskeletal strength.
Backing Up
There are many exercises you can do to prepare your horse's body and strengthen his muscles for collection, some of which can be found in Understanding and Improving Engagement and Collection One of these includes backing up in-hand. Although this is not a natural movement for your horse, it's a low impact exercise and has many anatomical and biomechanical benefits.
Begin with just one or two steps and over time progress to 20 good quality, long marching backward steps with your horse's head as low as possible to encourage him to lift his back. Repeat this on a daily basis for your horse to really feel the benefits.
Follow this link to find the webinar Understanding and Improving Engagement and Collection