Curl-ups: Difference between revisions

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[[File:Curl-up.jpg|thumb|curl-up exercise ]]
[[File:Curl-up.jpg|thumb|curl-up exercise ]]


The curl-up exercise is one of the most common [[Exercises for Lumbar Instability|exercises]] that target the [[Abdominal Muscles|abdominal muscle]]<nowiki/>s. The curl-up requires use of the abdominal muscles to curl the upper body off the floor. Because it requires only a partial sit up, the hip flexors do not participate in the movement. Research has shown that in a full sit up the hip flexors do most of the work<ref>AZ central What Does the Curl Ups Test Measure?Available:https://healthyliving.azcentral.com/curl-ups-test-measure-10744.html (accessed 3.1.2022)</ref>.
The curl-up exercise is one of the most common [[Exercises for Lumbar Instability|exercises]] that target the [[Abdominal Muscles|abdominal muscle]]<nowiki/>s. The curl up exercise targets  the abdominal muscles and works on the endurance of the abdominals and hip-flexors, important in back support and [[Core Stability|core stability]].<ref>Top end sports [https://www.topendsports.com/testing/tests/abendur.htm Curl up] Available: https://www.topendsports.com/testing/tests/abendur.htm<nowiki/>(accessed 3.1.2022)</ref> Having abdominal muscles with high endurance helps prevent low-back pain.<ref name=":3" />


The curl up exercise targets  the abdominal muscles and works on the endurance of the abdominals and hip-flexors, important in back support and [[Core Stability|core stability]].<ref>Top end sports [https://www.topendsports.com/testing/tests/abendur.htm Curl up] Available: https://www.topendsports.com/testing/tests/abendur.htm<nowiki/>(accessed 3.1.2022)</ref>
The curl-up requires use of the abdominal muscles to curl the upper body off the floor. It requires only a partial sit up and hence the hip flexors do not participate in the movement. Research has shown that in a full sit up the hip flexors do most of the work<ref name=":3">AZ central What Does the Curl Ups Test Measure?Available:https://healthyliving.azcentral.com/curl-ups-test-measure-10744.html (accessed 3.1.2022)</ref>.


Curl-ups are performed in the crook-lying, supine position, by lifting the head, arms and upper trunk from the floor. Different curl-ups angles affect the abdominal muscles activity.<ref name=":0">Ha SY, Shin DC. The effects of curl-up exercise in terms of posture and muscle contraction direction on muscle activity and thickness of trunk muscles. Journal of Back and Musculoskeletal Rehabilitation. 2020 Feb 28(Preprint):1-7.</ref>
Curl-ups are performed in the crook-lying, supine position, by lifting the head, arms and upper trunk from the floor. Different curl-ups angles affect the abdominal muscles activity.<ref name=":0">Ha SY, Shin DC. The effects of curl-up exercise in terms of posture and muscle contraction direction on muscle activity and thickness of trunk muscles. Journal of Back and Musculoskeletal Rehabilitation. 2020 Feb 28(Preprint):1-7.</ref>
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== Risk Factors and Significance ==
== Risk Factors and Significance ==
It is argued that the human spine can only handle a limited number of spine flexion cycles before it leads to  spinal [[Disc Herniation|disc herniation]], which is concluded from in-vitro studies on animal models. But this statement is criticised as the animal models can’t be compared to the human spine in the natural setting due to the many differences such as:  
 
* the ROM of animals and humans spines
== Technique ==
* the lack of adaptive and remodelling mechanisms found in the natural in-vivo setting that is not found in-vitro
The curl-up involves flexion of the thoracic portion of the spine to lift the weight of the shoulders and head off the floor, using the rectus abdominis assisted by the abdominal obliques. The lumbar spine remains fixed during the movement. When the shoulders lift off the floor, the upper abdominals will contract harder to bring the torso forward for a more intense contraction. The hands are not placed behind the head as this encourages the subject to stress the neck and pull the head forward. <ref name=":4">Sports performance bulletin Abdominal strength training – the curl-up Available:https://www.sportsperformancebulletin.com/endurance-training/strength-conditioning-and-flexibility/abdominal-strength-training-curl/ (accessed 3.1.2022)</ref>
* lack of fluid inflow to the disc in the in-vitro models
 
* the period of increased spinal load during spinal flexion exercise is transient that it does not induce fluid loss and the compressive load on the spine decreases in the natural setting due to increase in the intra-abdominal pressure which reduces the compressive forces on the spine.
* Start in supine with with knees bent and feet comfortably flat on the floor;
Spine flexion exercises have significance over the static ones as the spinal motion facilitates nutrients delivery to the intervertebral discs through loading and unloading cycles which is of significant importance as the primary cause of disc degeneration is the age related decrease in the disc nutritional status. Also, flexion-based spinal movements target the rectus abdominis more than other exercises.<ref name=":1">Contreras B, Schoenfeld B. [https://journals.lww.com/nsca-scj/Fulltext/2011/08000/To_Crunch_or_Not_to_Crunch__An_Evidence_Based.2.aspx To crunch or not to crunch: An evidence-based examination of spinal flexion exercises, their potential risks, and their applicability to program design.] Strength & Conditioning Journal. 2011 Aug 1;33(4):8-18.</ref>
* Adjust the pelvis so that the lumbar spine is in the neutral position.  
* Curl up your head and bring your chin towards your chest, fixing your neck position as if you were holding an tennis ball between your chin and neck;
* Hands placed behind ears with elbows pointing out to the side.
* Focus on abdominals, curling upper back off the floor, not moving any other body part, keeping arms, shoulders, neck and legs relaxed as the abs pull you up. If the movement is performed correctly, the head and arms will curl up as one unit with your shoulders;
* Stop when the upper back is off the floor.  
* Pause for one count at the top.
* Slowly lower the upper back down to the floor<ref name=":4" />


== Clinical Application ==
== Clinical Application ==
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A minimum of 48 hour to 72 hour rest should be allocated between dynamic spinal flexion exercise to allow the spinal tissue, muscles and intervertebral discs to remodel.
A minimum of 48 hour to 72 hour rest should be allocated between dynamic spinal flexion exercise to allow the spinal tissue, muscles and intervertebral discs to remodel.


Spinal flexion exercise shouldn’t be done until 1 hour of waking up, to decrease the risk of injury.<ref name=":1" /><br>
Spinal flexion exercise shouldn’t be done until 1 hour of waking up, to decrease the risk of injury.<ref name=":1">Contreras B, Schoenfeld B. [https://journals.lww.com/nsca-scj/Fulltext/2011/08000/To_Crunch_or_Not_to_Crunch__An_Evidence_Based.2.aspx To crunch or not to crunch: An evidence-based examination of spinal flexion exercises, their potential risks, and their applicability to program design.] Strength & Conditioning Journal. 2011 Aug 1;33(4):8-18.</ref><br>


'''The angle of the exercise''' is an important factor in the activity of the abdominal muscles. Maximum activity of the abdominal muscles  was reported at 30 degrees eccentric curl-up angle, which is achieved by lifting only the shoulders from the floor.
'''The angle of the exercise''' is an important factor in the activity of the abdominal muscles. Maximum activity of the abdominal muscles  was reported at 30 degrees eccentric curl-up angle, which is achieved by lifting only the shoulders from the floor.

Revision as of 02:30, 3 January 2022

Original Editor - Lilian Ashraf

Top Contributors - Lucinda hampton, Sheik Abdul Khadir, Lilian Ashraf, Daan Vandebriel and Wanda van Niekerk  

Introduction[edit | edit source]

curl-up exercise

The curl-up exercise is one of the most common exercises that target the abdominal muscles. The curl up exercise targets the abdominal muscles and works on the endurance of the abdominals and hip-flexors, important in back support and core stability.[1] Having abdominal muscles with high endurance helps prevent low-back pain.[2]

The curl-up requires use of the abdominal muscles to curl the upper body off the floor. It requires only a partial sit up and hence the hip flexors do not participate in the movement. Research has shown that in a full sit up the hip flexors do most of the work[2].

Curl-ups are performed in the crook-lying, supine position, by lifting the head, arms and upper trunk from the floor. Different curl-ups angles affect the abdominal muscles activity.[3]

Active Muscles[edit | edit source]

The abdominal muscles mainly activated are the rectus abdominis, external oblique, internal oblique and transversus abdominis.[3]

Risk Factors and Significance[edit | edit source]

Technique[edit | edit source]

The curl-up involves flexion of the thoracic portion of the spine to lift the weight of the shoulders and head off the floor, using the rectus abdominis assisted by the abdominal obliques. The lumbar spine remains fixed during the movement. When the shoulders lift off the floor, the upper abdominals will contract harder to bring the torso forward for a more intense contraction. The hands are not placed behind the head as this encourages the subject to stress the neck and pull the head forward. [4]

  • Start in supine with with knees bent and feet comfortably flat on the floor;
  • Adjust the pelvis so that the lumbar spine is in the neutral position.
  • Curl up your head and bring your chin towards your chest, fixing your neck position as if you were holding an tennis ball between your chin and neck;
  • Hands placed behind ears with elbows pointing out to the side.
  • Focus on abdominals, curling upper back off the floor, not moving any other body part, keeping arms, shoulders, neck and legs relaxed as the abs pull you up. If the movement is performed correctly, the head and arms will curl up as one unit with your shoulders;
  • Stop when the upper back is off the floor.
  • Pause for one count at the top.
  • Slowly lower the upper back down to the floor[4]

Clinical Application[edit | edit source]

To avoid over-stressing the spinal tissues it is recommended that the core strengthening routine does not exceed 60 repetitions of lumbar flexion cycles. For untrained individuals the training should start with a low volume 2 sets of 15 repetitions then progressively increase.

A minimum of 48 hour to 72 hour rest should be allocated between dynamic spinal flexion exercise to allow the spinal tissue, muscles and intervertebral discs to remodel.

Spinal flexion exercise shouldn’t be done until 1 hour of waking up, to decrease the risk of injury.[5]

The angle of the exercise is an important factor in the activity of the abdominal muscles. Maximum activity of the abdominal muscles  was reported at 30 degrees eccentric curl-up angle, which is achieved by lifting only the shoulders from the floor.

The activity of the abdominal muscles (rectus abdominis, external oblique and internal oblique) decrease as the curl-up angle increase (moving the body towards the vertical position) due to decrease in the body resistance torque.

The transverses abdominis muscle acts as a corset contributing to the inter-segmental control of the lumbar spine, rather than contributing in trunk flexion.[3]

The speed of the exercise is also an important factor as, the faster the curl-up exercise is performed the higher the muscles' activation level but the lower the motor control level which could lead to increased risk of injury. So it is necessary that the exercise is done at an optimal speed that allows both maximum activation of the abdominal muscles and adequate motor control. Barbado et al.(2015)[6] concluded that for active individuals the fastest cadence is 1 repetition/1 s that could be used but other for other less active populations a slower curl-up speed is recommended to decrease the risk of injury and allow for motor control.[6]


References[edit | edit source]

  1. ↑ Top end sports Curl up Available: https://www.topendsports.com/testing/tests/abendur.htm(accessed 3.1.2022)
  2. ↑ 2.0 2.1 AZ central What Does the Curl Ups Test Measure?Available:https://healthyliving.azcentral.com/curl-ups-test-measure-10744.html (accessed 3.1.2022)
  3. ↑ 3.0 3.1 3.2 Ha SY, Shin DC. The effects of curl-up exercise in terms of posture and muscle contraction direction on muscle activity and thickness of trunk muscles. Journal of Back and Musculoskeletal Rehabilitation. 2020 Feb 28(Preprint):1-7.
  4. ↑ 4.0 4.1 Sports performance bulletin Abdominal strength training – the curl-up Available:https://www.sportsperformancebulletin.com/endurance-training/strength-conditioning-and-flexibility/abdominal-strength-training-curl/ (accessed 3.1.2022)
  5. ↑ Contreras B, Schoenfeld B. To crunch or not to crunch: An evidence-based examination of spinal flexion exercises, their potential risks, and their applicability to program design. Strength & Conditioning Journal. 2011 Aug 1;33(4):8-18.
  6. ↑ 6.0 6.1 Barbado D, Elvira JL, Moreno FJ, Vera-Garcia FJ. Effect of performance speed on trunk movement control during the curl-up exercise. Journal of human kinetics. 2015 Jun 1;46(1):29-37.
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