Posture Analysis in the Sagittal Plane—Practical Guidelines with Reference Values

Abstract

Background: The alignment of a person’s body segments depends on their innate anatomy and neuromuscular status. Sagittal posture assessments provide valuable information on correctable deficits, which can be used to prevent possible health issues or injuries. Methods: This article provides practical guidance on how to perform a basic photometric sagittal posture analysis in a reproducible manner, which reference points should be used, and which errors should be avoided. For this purpose, based on the current literature, four important evidence-based parameters for evaluation are defined, and literature-based reference values are given for the assessment of posture. Conclusions: When done correctly, the sagittal posture analysis is a valuable tool in the fields of medicine and sports.

1. Introduction

Posture assessment is an important diagnostic tool in clinical practice and sports [1,2,3,4]. In particular, the lateral view provides information about typical postural defects in several body segments that may be associated with the onset of complaints. In an extensive review, Potthoff et al. called for a more detailed investigation into sagittal posture’s status as a risk factor for the onset of lower back pain in adolescence [5]. In this context, Sugai and colleagues were able to show that measuring thoracic kyphosis in older adults can predict future declines in their activities of daily living [6]. Regular posture assessments can, therefore, help to identify posture deficits at an early stage, enabling preventive measures to be implemented and can thus be an important tool for promoting public health.

However, determining the points at which posture deviation can still be considered normal and at which it must be considered a pathological disorder requiring treatment is difficult [7]. Since posture parameters can change over the course of a lifetime and sex-specific differences exist, it is useful to collect practical reference data to support medical diagnoses. Apart from radiological methods, which are usually inadequate in the field of posture prevention [8,9,10], non-invasive, optically based examination methods such as photogrammetry are used most frequently [11]. Therefore, only reference values that are not determined via radiological or 3D-stereophotogrammetric methods are presented in this article, since these are either invasive or technically demanding and cost-intensive and are therefore less suitable for preventive medical check-ups. In order to measure reproducible parameters, whether in the fields of medicine or sport, posture measurement parameters must fulfill the following conditions in order to be suitable for screening and preventive examinations of posture in everyday medical, physiotherapeutic or occupational contexts (see also [12]):

(1)

The parameters should be measurable with simple methods, without great effort or cost-intensive instruments, and in an objective, reliable and valid manner.

(2)

The parameters should be able to capture several areas in the sagittal plane since the transitional areas (lumbosacral transition and thoraco-cervical transition) are particularly critical in terms of stress [13].

(3)

Reference values should be available in order to provide a basis for deciding when posture parameters deviate from the norm depending on age and sex.

In this context, measurable parameters are helpful because they are superior to subjective assessments, which heavily depend on the experience of the examiner [14]. A large number of possible parameters are currently available, but they are also defined and measured differently depending on the study. In order to provide those working in the field of posture analysis with a practical overview, we have reviewed the literature and compiled analysis parameters that are useful for a sagittal analysis. On the basis of this evaluation, this article summarizes four global and local parameters that can be easily measured and have useful, practical applications; descriptions of the required anatomical reference points are also given.

In the following section, only those parameters are described on the basis of available studies that have a possible correlation with complaints. Subsequently, four posture parameters are presented based on the three criteria above, knowing that a large number of other parameters have been described in the literature (e.g., see [15]).

2. Examination Methodology

2.1. Preparation of the Test Subjects

The procedure for a posture analysis and the preparation of the subject are described relatively consistently in the literature [16,17]. In order to evaluate posture as accurately as possible, it is important to visualize as much of the body contours as possible. Simply put, the less clothing the test subject is wearing, the better. Since it may not be possible to undress the subject to a certain extent depending on the examination setting, compromises can be made, although these come at the expense of accuracy. Figure 1 shows the same subject being examined in different settings (left: workplace; right: doctor’s or physiotherapist’s office). Most markers can be attached to the skin except for the marker point on the greater trochanter. However, it is clear that the T-shirt being worn obscures the back contour, and therefore, no statements can be made about local misalignments in this body segment.

Table 1. Conditions for reproducible measurements of posture.

No.	Condition
1	As little clothing as possible
2	Feet shoulder-width apart
3	Knees pointing forward
4	Knee joints stretched
5	Upper limb hanging loosely, palms facing the body
6	Head straight (Frankfurt plane horizontal)
7	Relaxed breathing
8	Posture relaxed, not consciously tense
9	No talking
10	No prior muscular exhaustion

summarizes the essential orientation parameters for reproducibly measuring posture. Ideally, the subject should stand in their underwear.

With regard to point (3), it should be noted that in the case of forward-facing knee joints (the examiner can grasp them from the front to verify their position), the iliofemoral ligaments in the hip joints are not sufficiently tensed to change the alignment of the pelvis. As a rule, the feet (reference point: interdigital space 1–2) are then rotated outwards by about 5–10°. The position of the lower legs can be corrected by turning the feet until the knee joints are straight.

The knee joints should be extended, and the upper limbs should hang down loosely. The forearms should be slightly medially rotated so that the palms face the body (neutral zero position). A holding position is occasionally seen where the arms are crossed in front of the chest. This changes the position of the center of gravity, usually leading to an increase in thoracic kyphosis, and is therefore not recommended. The examiner can easily correct the arms so that they do not cover the marker point on the greater trochanter.

The head should be straight, the so-called Frankfurt plane should be horizontal, and the gaze should be facing straight ahead.

In the case of nervous subjects, it is important to ensure that their breathing is not held back. Overall, it is important to create a pleasant and relaxed atmosphere for the subject; only then can the body posture be measured undisturbed.

2.2. Marker Points and Balls

Standard adhesive dots with a diameter of 10–15 mm are suitable as marking points. For landmarks on the back and pelvis that would otherwise not be visible from the side, polystyrene balls with a diameter of 10–15 mm are recommended [18]. They are light and can be easily attached to the skin using thin, double-sided adhesive pads. Beforehand, the skin should be cleaned with alcohol and shaved if necessary so that the adhesive dots stick.

We recommend using the following landmarks to ensure a meaningful analysis of the sagittal plane [19]:

• Lateral malleolus: This landmark can be easily palpated even through socks. The marker should be placed at the center.
• Greater trochanter: The greater trochanter has a significant spatial extent, and as such its center point, projected onto the skin, is difficult to palpate in a reproducible manner. Underwear should be gathered since any point placed on it will shift with the movements of the test subject. Precise positioning on a pair of trousers, as shown in Figure 1, requires a lot of experience.
• Acromion: The acromion can be easily palpated with a little experience. If problems arise, it is recommended to palpate from the clavicle toward the acromioclavicular joint. The marker should be placed on the tip of the acromion process. Here, too, placement on the skin and not on the clothing is important. T-shirts can be gathered up at the sleeve and fixed with tape so that the point can be placed securely.
• C7: The spinous process of the seventh cervical vertebra is usually easily palpable and prominently visible. Sometimes, it is difficult to distinguish it from T1, depending on the individual’s anatomical characteristics. To differentiate them, the spinous process should be palpated and the subject should rotate their head to the left and right. The spinous process of C7 moves at the endpoint of the rotation, but T1 usually remains stationary.
• S1: The spinous process of the first sacral vertebra can be easily located by first identifying the PSIS. It is about the width of a thumb above (Figure 2).
• PSIS: The posterior superior iliac spines are located beneath the lumbar dimples. The level of the dimples approximately corresponds to the level of S2. When placing a hand on the iliac crest with the index finger to the side, the horizontally spread thumb points toward the PSISs. When palpating, move the finger you are using to palpate slightly so that you can feel the roughness beneath the skin (Figure 2).
• ASIS: The anterior superior iliac spines are easy to palpate because the iliac crest bends forward at this point.

Further instructions on how to palpate the anatomical landmarks accurately can be found in [20].

2.3. Measuring Station

If angles and perpendicular distances are to be measured reproducibly and accurately, a standardized and evenly illuminated measuring station should be set up (Figure 3). A floor mat with foot silhouettes printed on it can be used to place the test subject in a defined way. We provide a graphical file for this as Supplementary Materials Figure S1.

Webcams with HD resolution (1080 dpi) mounted on a tripod are suitable for use as cameras in the process. For image recording, the tripod should be set to a height that roughly corresponds to the height of the test subject’s belly button. This minimizes image distortion.

If the camera is tilted even slightly to the side, all angles that relate to the position of the test subject in the room (so-called “global” parameters) are inaccurate and can no longer be evaluated. Slight tilting cannot be seen with the naked eye, so we recommend the following procedure:

Place the test subject in front of a calibration wall that has vertical and horizontal reference lines. This allows the global angle reference frame to be determined in a reproducible manner in the posture photograph. With the help of a self-leveling laser plummet, an additional vertical line can be projected onto the subject or the calibration wall to correct possible plumb deviations. This is useful if the calibration panel is a mobile roll-up instead of being permanently mounted in a lab. In Supplementary Materials Figure S2, we provide a graphical file for a measuring panel that can be used freely.

2.4. Posture Measurement

When taking photographs or video sequences, it is important to ensure that the camera is positioned at the subject’s belly button height and that the optical axis is perfectly aligned with the subject to avoid parallax errors. The subject should stand still.

2.5. Analysis

The posture photographs can be analyzed using appropriate video or graphical programs (e.g., Dartfish^®, Fribourg, Switzerland; or Kinovea^®, www.kinovea.org accessed on 7 March 2025). When measuring angles, care should be taken to align the vertical or horizontal reference planes using the reference lines on the calibration wall to avoid possible camera tilt.

3. Examination Parameters

Posture parameters are divided into global parameters, which indicate the alignment of the body in relation to the fixed world coordinate system (e.g., body lean), and parameters that capture the positions of individual segments in relation to each other (e.g., pelvic tilt and craniovertebral angle) [21]. The suggested parameters provide a good overall view of posture and are linked to both reference values and specific studies that have been able to establish correlations with complaints.

3.1. Overview of Lateral Posture

3.1.1. Theoretical Background

With regard to the sagittal plane, it is generally accepted that the head, trunk and pelvis should be perpendicular to the ground in an upright posture in order to achieve a state of equilibrium characterized by dynamic stability and low muscle activity [22,23]. Debousset defines the corresponding geometric “conus of economy” [9].

3.1.2. Anatomical Landmarks

The primary anatomical landmarks used for sagittal posture analysis (Figure 1) are the external auditory canal (meatus acusticus externus), more specifically, the center of the tragus, the acromion (shoulder height) and the trochanter major (greater trochanter) [19]. The external malleolus or a point located 1–2 cm distal to it (at the calcaneo-cuboid joint) serves as the reference point for the plumb line, through which the projection of the center of mass usually runs.

The perpendicular alignment of the body as a normal posture was propagated by the Kendalls [22] and adopted by other authors with variations in the reference points and their perpendicular alignment.

3.1.3. Recommendations

When looking at a plumb line projected onto the body from the side, one can obtain an initial overview of the segments that deviate significantly from the plumb line (Figure 3). Even though there are no reference values for the magnitude of plumb line deviation, the following test procedures can be selected on this basis to conduct more in-depth analyses of postural weaknesses in individual segments that deviate from the plumb line.

3.2. Anteversion of the Pelvis—Pelvic Tilt

3.2.1. Theoretical Background

Since the pelvis is the basis for the alignment of the spine, examining its positioning in the sagittal plane is particularly important [24]. Anatomically, anterior pelvic tilt (“anteversion”) can lead to an anterior tilt of the lumbosacral transition area and frequently to an increase in lumbar lordosis [25]. This, in turn, can lead to lower back pain [26,27]. Tilting the pelvis backward, on the other hand, results in a steep position of the sacrum with a flat lumbar lordosis.

There is a correlation between a more tilted pelvis and the occurrence of lower back pain [28,29]. Current research has shown that the anteversion of the pelvis in the sagittal plane can also influence the incidence of muscle injuries in sports. Bayrak and Patlar showed that an increase in pelvic tilt beyond a cut-off angle of 13° was associated with a higher incidence of hamstring injuries [30]. Due to its anatomical position, the biceps femoris muscle is particularly susceptible to increased tension [31], which can be caused by increased pelvic tilt. Mendiguchia et al. found that tension increased in the proximal hamstring muscle origin with increasing pelvic tilt [32]. A higher risk of hamstring injury due to fatigue-related increases in pelvic tilt was also observed by Romero et al. [33].

3.2.2. Anatomical Landmarks

Figure 4 shows the marker placements on the anterior superior iliac spine (ASIS) and the posterior superior iliac spine (PSIS). The pelvic tilt is the angle between the line connecting the two markers and the horizontal plane.

3.2.3. Reference Values

Reference values for pelvic tilt have been provided for various populations in several studies.

Table 2. Mean values, standard deviations and 95% confidence intervals (CI) of pelvic tilt from various studies.

Study	Sex, Number	Mean Value	Standard Deviation	95% CI	Method	Remarks
Bibrowicz et al., 2022 [34]	W, n = 176	15.8	3.5	15.3–16.3	I
	M, n = 170	14.9	3.3	14.1–15.4	I
Yoon, 2020 [35]	W, n = 61	10.9	5.4	9.5–12.3	I
	M, n = 44	8.4	5.2	6.9–9.9	I
Krawczky et al., 2014 [36]	M + W n = 94	12.3	5.8	11.1–13.5	--	Weighted average of 4 studies
Sinzato et al., 2013 [37]	W, n = 33 2 subgroups	16.1	4.1	14.7–17.5	P	Initial values of a treatment and a control group
		13.4	4.2	11.6–15.2	P
Glaner et al., 2012 [38]	W, n = 30	12.6	4.2	11.1–14.1	P
Carregaro et al., 2012 [39]	W, n = 24	15.0	6.3	12.5–17.5	P
	M, n = 13	9.5	3.8	7.4–11.6	P
Herrington, 2011 [40]	M, n = 55	6.74	n.r.		I
	W, n = 41	6.93	n.r.
Moraes et al., 2010 [41]	W, n = 15	12.4	4.3	10.2–14.6	P
Nguyen & Shultz, 2007 [42]	W, n = 50	12.2	5.2	10.8–13.6	I
	M, n = 50	8.6	4.2	7.4–9.8	I

I—inclinometer, P—photogrammetry, n.r.—value not reported.

shows an overview of the reported values.

This overview shows how inconsistent the mean values found are, which may be partly due to the different measurement methods used (inclinometer versus photogrammetry), the experience of the examiners and the age groups examined (in the studies listed in Table 2, mostly younger individuals were examined). Nevertheless, the anatomical values shown for women are greater than those for men.

Based on the results obtained by Bayrak and Patlar [30], values greater than 13° should be viewed critically in athletes.

3.2.4. Recommendation

Taking into account the measurement inaccuracies that can arise in photometric angle measurements, we recommend using the following rounded values based on the examinations described in Table 2:

• Pelvic tilt (men): 7°–15°;
• Pelvic tilt (women): 10°–17°;
• Pelvic tilt (athletes): <13°.

3.3. Forward Inclination of the Body—Body Lean

3.3.1. Theoretical Background

The inclination of the body in the sagittal plane is a global posture parameter that depends on the activity of the stabilizing muscle groups. In the ankle joint area, the activity of the calf muscles determines the forward inclination of the lower leg [43], while in the hip joint area, it is determined by the interaction between the hip and trunk extensors (e.g., the gluteus maximus and erector spinae muscles) and the hip and trunk flexors. This also results in a correlation between weak back muscles and the occurrence of lower back pain [5]. Correlations between body lean and back complaints have been shown in children and adolescents [44,45,46,47,48]. Interestingly, segmental misalignments of the spine (e.g., hyperkyphosis/hunchback or hyperlordosis/hollow back) are not included in the calculation of this global parameter.

3.3.2. Anatomical Landmarks

Figure 5 shows the positioning of the marker points on the lateral malleolus and the spinous process of the seventh cervical vertebra (C7). Body lean is defined as the angle between the line connecting the two markers and the vertical axis.

3.3.3. Reference Values

The values found for body lean in other studies are listed in

Table 3. Mean values, standard deviations and 95% confidence intervals (CI) of body lean from various studies.

Study	Sex, Number	Mean Value	Standard Deviation	95% CI	Remarks
Ferreira et al., 2011 [1]	M + W, n = 22	1.68	0.44	1.50–1.86
Carregaro et al., 2012 [39]	M, n = 13	1.60	0.42	1.37–1.83
	W, n = 24	0.99	0.24	0.89–1.09
Moraes et al., 2010 [41]	W, n = 15	2.16	1.09	1.61–2.71
Krawczky et al., 2014 [36]	M + W, n = 104	1.73	0.94	1.55–1.91	Weighted average of 4 studies
Dolphens et al., 2012 [49]	M, n = 639	0.00	1.12	−0.09–0.09	Boys, 12.6 ± 0.54 years
	W, n = 557	0.60	1.12	0.51–0.69	Girls, 10.6 ± 0.47 years

.

In order to establish reference values, Krawczky et al. evaluated data from four studies in a review [36] and determined the following values, irrespective of sex:

• Body lean: 1.73° ± 0.94°;
• 95% confidence interval [1.55°–1.91°].

In several scientific publications, Dolphens et al. examined body lean in children aged 10–12 years, among other parameters [21,44,50]. They were able to identify several clusters of posture types. Children with a more backward-leaning upper body position showed a significantly higher prevalence of back pain. The authors provided the following body lean values for this “sway back” cluster:

• Body lean: 1.3° ± 0.88°;
• 95% confidence interval [1.18°–1.42°].

3.3.4. Recommendations

Taking into account the measurement inaccuracies that can arise in photometric angle measurement, we recommend the following values based on the studies outlined in Table 2:

• Body lean (adults): 1.5°–1.6°;
• Body lean (children): <1.3°.

3.4. Forward Tilt of the Head—Craniovertebral Angle

3.4.1. Theoretical Background

The craniovertebral angle, or CVA (also referred to in other studies as the neck inclination angle, cervical angle or head protrusion angle), is a measure of the forward inclination of the head. The test quality criteria for this parameter (inter-rater and intra-rater reliability) have been confirmed [17]. For example, Salahzadeh et al. found an ICC of 0.90 for intra-rater reliability, 0.92 for inter-rater reliability and 0.96 for intra-subject reliability [51]. In general, the acute angle is calculated as shown in Figure 6; the smaller the angle, the more the head tilts forward. Since there is a correlation between a greater forward head tilt and the occurrence of shoulder and neck complaints [47,48,52], this parameter is useful in the context of posture diagnostics [2]. Likewise, a correlation is suspected between a smaller CVA and occlusal disorders [53].

3.4.2. Anatomical Landmarks

A marker ball positioned on C7 is sufficient; the auditory canal does not need to be marked. For the most accurate measurement, the leg of the angle should pass through the midpoint of the tragus of the ear. To minimize measurement errors, it is important that the head is straight and the gaze is directed forward (horizontal Frankfurt plane). If necessary, a marker point can be placed on a distant wall at which the subject focuses their gaze. The angle to the horizontal is measured. Since the angle is particularly sensitive to camera tilt, the horizontal leg of the angle should be aligned with a reference line in the image (Figure 6). A calibration panel (see Supplementary Materials Figure S2) is useful for this purpose.

3.4.3. Reference Values

Table 4. Mean values, standard deviation and 95%-confidence interval (CI) for the craniovertebral angle in the analyzed studies.

Study	Sex, Number	Mean Value Obtuse Angle	Mean Value Acute Angle	Standard Deviation	95% CI	Remarks
Kim et al., 2018 [52]	M + W, n = 22	131.4	48.6	1.99	47.8–49.3	Adults
Hazar et al., 2015 [55]	M + W, n = 30	131.6	48.4	4.9	46.7–50.2	Adolescents, 16 years
Helmya et al., 2015 [56]	M + W, n = 22	131.4	48.6	8.1	45.2–52.0	Adolescents, 12–18 years, average of 3 raters
Coelho et al., 2014 [57]	W, n = 15	135.6	44.4	6.69	41.0–47.8	Subgroup of children with normal flexibility, 7–12 years
	M, n = 6	137.1	42.9	2.01	41.3–44.5
Singla & Veqar, 2015 [58]	M, n = 15	129.7	50.3	3.56	48.5–52.1	Adults
Salahzadeh et al., 2015 [51]	W, n = 12	125.0	55.0	3.30	53.1–56.9	Adults
Greenfield et al., 1995 [59]	M + W, n = 30	128.0	52.0	4.7	50.3–53.7	Adults
Raine & Twomey, 1994 [60]	M + W, n = 39	128.1	51.9	4.5	50.5–53.3	Adolescents and adults

shows the mean values for the CVA (see also [17,54]). Since the definition of the CVA is not standardized, both the obtuse angle and the acute angle (180°—obtuse angle) are given.

3.4.4. Recommendations

Kim et al. [52] identified a range of 48.6° ± 2.0° (95% confidence interval: 47.8°–49.3°) for symptom-free subjects. The mean value for subjects with neck complaints was 44.4° ± 4.4° (95% confidence interval: 42.6°–46.3°). Salahzadeh et al. distinguished a normal CVA of 55.0 ± 3.3° from a moderate to severe head tilt with a CVA of 41.9 ± 3.9° [51].

The following values can therefore be recommended:

• Craniovertebral angle: 47°–50°.

3.5. Depth of Lordosis in the Cervical and Lumbar Spine—Fleche Cervicale and Lombaire

3.5.1. Theoretical Background

It is known that a particularly strong structural load is placed on the vertebrae and their joints, especially the facet joints, at the transition points between lordosis and kyphosis [13]. The posture parameters fleche cervicale and fleche lombaire are particularly interesting in this context because they are calculated using the differences in the peak points of kyphosis and lordosis in the sagittal plane (the term “flèche” comes from the French for arrow). Both parameters were introduced by Stagnara in 1982 [61,62]. Since they can be obtained quickly, inexpensively and almost without contact with the subject, these parameters are highly practical.

3.5.2. Anatomical Landmarks

A plumb line is placed at the point of the most pronounced thoracic kyphosis (apex). If the apex of the thoracic kyphosis is obscured by the scapulae, a measuring stick can also be adhered to the skin to precisely locate the position of the apex. The horizontal distances of the deepest cervical lordosis (fleche cervicale) and the deepest lumbar lordosis (fleche lombaire) to the plumb line are measured (Figure 7). Since taller individuals have anatomically more pronounced kyphoses and lordoses, it is recommended to normalize the fleche values to the trunk height [63]. For this purpose, the vertical distance between C7 and S1 is measured (equivalent to the trunk height), and the fleche values are normalized according to the following formula:

Fleche% = fleche * 100/(distance C7-S1).

An advantage of the fleche values is that they can be measured with minimal apparatus. All that is needed is a plumb line, a ruler (preferably with a spirit level) and a flexible measuring tape.

3.5.3. Reference Values

In a recent study [63], data from 1150 subjects of different ages were analyzed. The resulting values are summarized in

Table 5. Normalized values of fleche lombaire (FL%) and fleche cervicale (FC%) in different age groups for both sexes. Data adapted from [63] with permission.

Parameter	Age Group [Years]	Sex	N	Mean	25th Percentile	75th Percentile	Lower 95% CI	Upper 95% CI
FL% [% trunk height]	10–15	female	44	8.99	7.13	11.27	8.14	9.86
	12–16	male	159	7.13	5.06	8.74	6.70	7.60
	16–19 17–19	female	14	7.63	6.45	8.37	6.74	8.62
		male	29	7.29	5.41	9.50	6.21	8.44
	20–29	female	105	8.35	6.51	10.47	7.81	8.92
		male	126	7.62	5.79	9.31	7.11	8.14
	30–39	female	75	8.54	6.59	10.49	7.83	9.22
		male	90	7.85	5.72	9.98	7.24	8.49
	40–49	female	97	8.22	6.13	10.39	7.62	8.81
		male	98	7.43	5.37	9.44	6.84	7.97
	50–59	female	99	8.52	6.69	10.68	7.94	9.12
		male	144	7.65	5.78	9.59	7.22	8.11
	60–69	female	18	8.94	5.54	11.34	7.41	10.41
		male	29	7.41	5.74	9.31	6.51	8.28
FC% [% trunk height]	10–15	female	44	12.29	9.77	14.12	11.32	13.31
	12–16	male	159	13.04	11.13	15.13	12.57	13.53
	16–19	female	14	11.64	8.62	13.97	10.22	13.21
	17–19	male	29	12.60	10.76	13.44	11.65	13.51
	20–29	female	105	11.68	9.53	13.61	11.11	12.24
		male	126	12.89	10.59	14.86	12.33	13.43
	30–39	female	75	10.42	8.35	12.44	9.63	11.22
		male	90	13.11	11.42	15.08	12.54	13.67
	40–49	female	97	11.30	9.04	13.73	10.59	12.03
		male	98	14.13	12.45	16.21	13.54	14.71
	50–59	female	99	12.22	10.06	14.67	11.48	12.97
		male	144	14.69	12.37	16.65	14.13	15.25
	60–69	female	18	11.66	8.55	14.47	9.17	14.27
		male	29	14.68	12.44	16.68	13.40	15.94

.

3.5.4. Recommendations

The confidence intervals can be found in the Table 5. As a rule of thumb, the following can be assumed:

• Normalized FC for men: 12–15% of the trunk height;
• Normalized FC for women: 9.5–14% of the trunk height;
• Normalized FL for men: 6.5–8.5% of the trunk height;
• Normalized FL for women: 7–9% of the trunk height.

4. Conclusions

Posture analysis in the sagittal plane is useful from a preventative medical point of view, as there are relationships between deviations in individual posture parameters and the occurrence of complaints. The parameters presented in this article have all been scientifically evaluated, and reference values are available that make it possible to assess sagittal posture from a medical or sports science perspective. Even though photometric posture analysis is subject to measurement errors, it still allows for sufficiently accurate measurement and evaluation of posture if the anatomical landmarks are correctly palpated and marked. Therefore, sagittal posture analysis should also be increasingly used in the field of sports for preventive purposes.