Proper lifting technique and its phases are described along with its biomechanical components.

1. Biomechanics of lifting
Dr. Manasi Kulkarni
MPT-Neurophysiotherapy
Guide: Dr. Suvarna Ganvir
D.V.V.P.F’s College of Physiotherapy, Ahmednagar

2. Content
 What is Lifting?
 Components of Lifting
 Types of Lifting
 Stability of Load

3. Lifting
 Lifting is an activity that is an essential part of everyday life.
 Unfortunately, it has been implicated as a contributing factor
in the development of a variety of musculoskeletal injuries,
particularly those that involve the lumbar spine

4. Components of Lifting
 Lifting involves movement of an object from one location to another
location, generally traversing both vertical and horizontal distances.
 This, can be subdivided into three stages:
– Access
– Movement
– Placement

5. Types of lifting
 Stoop Lifting  Squat Lifting

6. Stoop Lifting
 Trunk flexion achieved by thoracolumbar flexion and there is no knee
flexion.
 The extensor muscles are at a disadvantage , because of shorter
moment arms in this position, a change in the line of pull and the
possibility of passive insufficiency resulting from elongated state of
muscles.
 Intradiscal pressure higher.

7.  Knee-High quadriceps femoris group activity at the beginning and at
the end of the lift
 Moderate use of hamstrings occurs in the middle third of the lift.
 The erector spinae in flexed posture have changed line of actions
relative to the motion segment and are therefore less able to resist
the anterior shear forces seen to cause damage to the spine in full
flexion.

8. Squat Lifting
 Spine remains as erect as possible and trunk flexion achieved
primarily by hip and knee flexion.
 The deep layer of erector spinae is capable of producing posterior
shear, which helps to offset anterior shear that occurs with trunk
flexion, in case of carrying additional load.
 Intradiscal pressure comparatively lower

9.  Knee-The flexion moment at the beginning of the lift changes to an
extension moment.
 Medium to high activity of vastus lateralis, less activity of rectus femoris
and low to medium activity of biceps femoris.
 Contraction of erector spinae muscles results in the development of a
posterior shear force on the superior vertebrae. This has the potential
effect of reducing the effect of anterior shear forces generated by the
weight of the upper trunk and load

11. Load

12. Stability of the load
 Keep the load close :– Documented reduction in lumbar stress.
 Ensure the placement of a secure hand couple:
– Minimizes trunk instability during a lift involving asymmetric handling and load
shift.
 Use the lifting technique that is most applicable to the situation:–.
– Squat lift- To be used as an alternative to the semi-squat when space is limited
and load size does not allow for foot placement to the side of the object to be
lifted.

13. - Semi squat lift- This would be the ideal lift for heavy loads performed on
an occasional basis.
- Stoop lift- Lifting scenarios requiring light loads (20 pounds and below) on
a frequent basis are more efficiently managed using this technique.
 When lifting on an uneven-sloped surface, face down the slope to
negotiate the lift.
 When lifting, do so as much as is possible in the sagittal plane.

14. Thank You